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From: Alex Khatskevich <avkhatskevich@tarantool.org>
To: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>,
	tarantool-patches@freelists.org
Subject: [tarantool-patches] Re: [PATCH 3/3] Introduce multiple routers feature
Date: Tue, 7 Aug 2018 16:18:25 +0300	[thread overview]
Message-ID: <e98bf0e4-6014-7947-5871-ed802a8b11eb@tarantool.org> (raw)
In-Reply-To: <9109c71a-0313-82c8-02db-3e4dd8c833cd@tarantool.org>

On 06.08.2018 20:03, Vladislav Shpilevoy wrote:
> Thanks for the patch! See 8 comments below.
>
> 1. You did not send a full diff. There are tests only. (In
> this email I pasted it myself). Please, send a full diff
> next times.
Ok, sorry.
>
>>>> +    if M.routers[name] then
>>>> +        return nil, string.format('Router with name %s already 
>>>> exists', name)
>>>> +    end
>>>> +    local router = table.deepcopy(ROUTER_TEMPLATE)
>>>> +    setmetatable(router, router_mt)
>>>> +    router.name = name
>>>> +    M.routers[name] = router
>>>> +    if name == STATIC_ROUTER_NAME then
>>>> +        M.static_router = router
>>>> +        export_static_router_attributes()
>>>> +    end
>>>
>>> 9. This check can be removed if you move
>>> export_static_router_attributes call into legacy_cfg.
>> Butbue to this if, the static router can be configured by
>> `vshard.box.new(static_router_name)`.
>
> 2. It is not ok. A user should not use any internal names like
> _statis_router to configure it and get. Please, add a new member
> vshard.router.static that references the statis one. Until cfg
> is called it is nil.
Fixed.
By now, user can create a static router only by calling 
`vshard.router.cfg()`
>
>> diff --git a/vshard/router/init.lua b/vshard/router/init.lua
>> index 3e127cb..62fdcda 100644
>> --- a/vshard/router/init.lua
>> +++ b/vshard/router/init.lua
>> @@ -25,14 +25,32 @@ local M = rawget(_G, MODULE_INTERNALS)
>>  if not M then
>>      M = {
>>          ---------------- Common module attributes ----------------
>> -        -- The last passed configuration.
>> -        current_cfg = nil,
>>          errinj = {
>>              ERRINJ_CFG = false,
>>              ERRINJ_FAILOVER_CHANGE_CFG = false,
>>              ERRINJ_RELOAD = false,
>>              ERRINJ_LONG_DISCOVERY = false,
>>          },
>> +        -- Dictionary, key is router name, value is a router.
>> +        routers = {},
>> +        -- Router object which can be accessed by old api:
>> +        -- e.g. vshard.router.call(...)
>> +        static_router = nil,
>> +        -- This counter is used to restart background fibers with
>> +        -- new reloaded code.
>> +        module_version = 0,
>> +        collect_lua_garbage_cnt = 0,
>
> 3. A comment?
added
-- Number of router which require collecting lua garbage.
>
>> +    }
>> +end
>> +
>> +--
>> +-- Router object attributes.
>> +--
>> +local ROUTER_TEMPLATE = {
>> +        -- Name of router.
>> +        name = nil,
>> +        -- The last passed configuration.
>> +        current_cfg = nil,
>>          -- Time to outdate old objects on reload.
>>          connection_outdate_delay = nil,
>>          -- Bucket map cache.> @@ -488,8 +505,20 @@ end
>>  -- Configuration
>>  -------------------------------------------------------------------------------- 
>>
>>
>> -local function router_cfg(cfg)
>> -    local vshard_cfg, box_cfg = lcfg.check(cfg, M.current_cfg)
>> +local function change_lua_gc_cnt(val)
>
> 4. The same.
fixed
>
>> +    assert(M.collect_lua_garbage_cnt >= 0)
>> +    local prev_cnt = M.collect_lua_garbage_cnt
>> +    M.collect_lua_garbage_cnt = M.collect_lua_garbage_cnt + val
>> +    if prev_cnt == 0 and M.collect_lua_garbage_cnt > 0 then
>> +        lua_gc.set_state(true, consts.COLLECT_LUA_GARBAGE_INTERVAL)
>> +    end
>> +    if prev_cnt > 0 and M.collect_lua_garbage_cnt == 0 then
>> +        lua_gc.set_state(false, consts.COLLECT_LUA_GARBAGE_INTERVAL)
>> +    end
>
> 5. You know the concrete val in the caller always: 1 or -1. I think
> it would look simpler if you split this function into separate inc
> and dec ones. The former checks for prev == 0 and new > 0, the later
> checks for prev > 0 and new == 0. It is not needed to check both
> each time.
changed
>
>> +end
>> +
>> +local function router_cfg(router, cfg)
>> +    local vshard_cfg, box_cfg = lcfg.check(cfg, router.current_cfg)
>>      if not M.replicasets then
>>          log.info('Starting router configuration')
>>      else
>> @@ -803,6 +839,77 @@ if M.errinj.ERRINJ_RELOAD then
>>      error('Error injection: reload')
>>  end
>>
>> +-------------------------------------------------------------------------------- 
>>
>> +-- Managing router instances
>> +-------------------------------------------------------------------------------- 
>>
>> +
>> +local function cfg_reconfigure(router, cfg)
>> +    return router_cfg(router, cfg)
>> +end
>> +
>> +local router_mt = {
>> +    __index = {
>> +        cfg = cfg_reconfigure;
>> +        info = router_info;
>> +        buckets_info = router_buckets_info;
>> +        call = router_call;
>> +        callro = router_callro;
>> +        callrw = router_callrw;
>> +        route = router_route;
>> +        routeall = router_routeall;
>> +        bucket_id = router_bucket_id;
>> +        bucket_count = router_bucket_count;
>> +        sync = router_sync;
>> +        bootstrap = cluster_bootstrap;
>> +        bucket_discovery = bucket_discovery;
>> +        discovery_wakeup = discovery_wakeup;
>> +    }
>> +}
>> +
>> +-- Table which represents this module.
>> +local module = {}
>> +
>> +-- This metatable bypasses calls to a module to the static_router.
>> +local module_mt = {__index = {}}
>> +for method_name, method in pairs(router_mt.__index) do
>> +    module_mt.__index[method_name] = function(...)
>> +        return method(M.static_router, ...)
>> +    end
>> +end
>> +
>> +local function export_static_router_attributes()
>> +    setmetatable(module, module_mt)
>> +end
>> +
>> +local function router_new(name, cfg)
>
> 6. A comment?
added
>
> 7. This function should not check for router_name == static one.
> It just creates a new router and returns it. The caller should set
> it into M.routers or M.static_router if needed. For a user you
> expose not this function but a wrapper that calls router_new and
> sets M.routers.
fixed.
>
>> +    if type(name) ~= 'string' or type(cfg) ~= 'table' then
>> +           error('Wrong argument type. Usage: 
>> vshard.router.new(name, cfg).')
>> +    end
>> +    if M.routers[name] then
>> +        return nil, string.format('Router with name %s already 
>> exists', name)
>> +    end
>> +    local router = table.deepcopy(ROUTER_TEMPLATE)
>> +    setmetatable(router, router_mt)
>> +    router.name = name
>> +    M.routers[name] = router
>> +    if name == STATIC_ROUTER_NAME then
>> +        M.static_router = router
>> +        export_static_router_attributes()
>> +    end
>> +    router_cfg(router, cfg)
>> +    return router
>> +end
>> +
>> @@ -813,28 +920,23 @@ end
>>  if not rawget(_G, MODULE_INTERNALS) then
>>      rawset(_G, MODULE_INTERNALS, M)
>>  else
>> -    router_cfg(M.current_cfg)
>> +    for _, router in pairs(M.routers) do
>> +        router_cfg(router, router.current_cfg)
>> +        setmetatable(router, router_mt)
>> +    end
>>      M.module_version = M.module_version + 1
>>  end
>>
>>  M.discovery_f = discovery_f
>>  M.failover_f = failover_f
>> +M.router_mt = router_mt
>> +if M.static_router then
>> +    export_static_router_attributes()
>> +end
>
> 8. This is possible on reload only and can be moved into
> the if above to the reload case processing.
Fixed.


Here is a full diff


commit 87b6dc044de177e159dbe24f07abf3f98839ccff
Author: AKhatskevich <avkhatskevich@tarantool.org>
Date:   Thu Jul 26 16:17:25 2018 +0300

     Introduce multiple routers feature

     Key points:
     * Old `vshard.router.some_method()` api is preserved.
     * Add `vshard.router.new(name, cfg)` method which returns a new router.
     * Each router has its own:
       1. name
       2. background fibers
       3. attributes (route_map, replicasets, outdate_delay...)
     * Module reload reloads all configured routers.
     * `cfg` reconfigures a single router.
     * All routers share the same box configuration. The last passed config
       overrides the global box config.
     * Multiple router instances can be connected to the same cluster.
     * By now, a router cannot be destroyed.

     Extra changes:
     * Add `data` parameter to `reloadable_fiber_create` function.

     Closes #130

diff --git a/test/failover/failover.result b/test/failover/failover.result
index 73a4250..50410ad 100644
--- a/test/failover/failover.result
+++ b/test/failover/failover.result
@@ -174,7 +174,7 @@ test_run:switch('router_1')
  ---
  - true
  ...
-rs1 = vshard.router.internal.replicasets[rs_uuid[1]]
+rs1 = vshard.router.internal.static_router.replicasets[rs_uuid[1]]
  ---
  ...
  while not rs1.replica_up_ts do fiber.sleep(0.1) end
diff --git a/test/failover/failover.test.lua 
b/test/failover/failover.test.lua
index 6e06314..44c8b6d 100644
--- a/test/failover/failover.test.lua
+++ b/test/failover/failover.test.lua
@@ -74,7 +74,7 @@ echo_count

  -- Ensure that replica_up_ts is updated periodically.
  test_run:switch('router_1')
-rs1 = vshard.router.internal.replicasets[rs_uuid[1]]
+rs1 = vshard.router.internal.static_router.replicasets[rs_uuid[1]]
  while not rs1.replica_up_ts do fiber.sleep(0.1) end
  old_up_ts = rs1.replica_up_ts
  while rs1.replica_up_ts == old_up_ts do fiber.sleep(0.1) end
diff --git a/test/failover/failover_errinj.result 
b/test/failover/failover_errinj.result
index 3b6d986..484a1e3 100644
--- a/test/failover/failover_errinj.result
+++ b/test/failover/failover_errinj.result
@@ -49,7 +49,7 @@ vshard.router.cfg(cfg)
  -- Check that already run failover step is restarted on
  -- configuration change (if some replicasets are removed from
  -- config).
-rs1 = vshard.router.internal.replicasets[rs_uuid[1]]
+rs1 = vshard.router.internal.static_router.replicasets[rs_uuid[1]]
  ---
  ...
  while not rs1.replica or not rs1.replica.conn:is_connected() do 
fiber.sleep(0.1) end
diff --git a/test/failover/failover_errinj.test.lua 
b/test/failover/failover_errinj.test.lua
index b4d2d35..14228de 100644
--- a/test/failover/failover_errinj.test.lua
+++ b/test/failover/failover_errinj.test.lua
@@ -20,7 +20,7 @@ vshard.router.cfg(cfg)
  -- Check that already run failover step is restarted on
  -- configuration change (if some replicasets are removed from
  -- config).
-rs1 = vshard.router.internal.replicasets[rs_uuid[1]]
+rs1 = vshard.router.internal.static_router.replicasets[rs_uuid[1]]
  while not rs1.replica or not rs1.replica.conn:is_connected() do 
fiber.sleep(0.1) end
  vshard.router.internal.errinj.ERRINJ_FAILOVER_CHANGE_CFG = true
  wait_state('Configuration has changed, restart ')
diff --git a/test/failover/router_1.lua b/test/failover/router_1.lua
index d71209b..664a6c6 100644
--- a/test/failover/router_1.lua
+++ b/test/failover/router_1.lua
@@ -42,7 +42,7 @@ end
  function priority_order()
      local ret = {}
      for _, uuid in pairs(rs_uuid) do
-        local rs = vshard.router.internal.replicasets[uuid]
+        local rs = vshard.router.internal.static_router.replicasets[uuid]
          local sorted = {}
          for _, replica in pairs(rs.priority_list) do
              local z
diff --git a/test/misc/reconfigure.result b/test/misc/reconfigure.result
index c7960b3..311f749 100644
--- a/test/misc/reconfigure.result
+++ b/test/misc/reconfigure.result
@@ -250,7 +250,7 @@ test_run:switch('router_1')
  -- Ensure that in a case of error router internals are not
  -- changed.
  --
-not vshard.router.internal.collect_lua_garbage
+not vshard.router.internal.static_router.collect_lua_garbage
  ---
  - true
  ...
@@ -264,7 +264,7 @@ vshard.router.cfg(cfg)
  ---
  - error: 'Incorrect value for option ''invalid_option'': unexpected 
option'
  ...
-not vshard.router.internal.collect_lua_garbage
+not vshard.router.internal.static_router.collect_lua_garbage
  ---
  - true
  ...
diff --git a/test/misc/reconfigure.test.lua b/test/misc/reconfigure.test.lua
index 25dc2ca..298b9b0 100644
--- a/test/misc/reconfigure.test.lua
+++ b/test/misc/reconfigure.test.lua
@@ -99,11 +99,11 @@ test_run:switch('router_1')
  -- Ensure that in a case of error router internals are not
  -- changed.
  --
-not vshard.router.internal.collect_lua_garbage
+not vshard.router.internal.static_router.collect_lua_garbage
  cfg.collect_lua_garbage = true
  cfg.invalid_option = 'kek'
  vshard.router.cfg(cfg)
-not vshard.router.internal.collect_lua_garbage
+not vshard.router.internal.static_router.collect_lua_garbage
  cfg.invalid_option = nil
  cfg.collect_lua_garbage = nil
  vshard.router.cfg(cfg)
diff --git a/test/multiple_routers/configs.lua 
b/test/multiple_routers/configs.lua
new file mode 100644
index 0000000..a6ce33c
--- /dev/null
+++ b/test/multiple_routers/configs.lua
@@ -0,0 +1,81 @@
+names = {
+    storage_1_1_a = '32a2d4b8-f146-44ed-9d51-2436507efdf8',
+    storage_1_1_b = 'c1c849b1-641d-40b8-9283-bcfe73d46270',
+    storage_1_2_a = '04e677ed-c7ba-47e0-a67f-b5100cfa86af',
+    storage_1_2_b = 'c7a979ee-9263-4a38-84a5-2fb6a0a32684',
+    storage_2_1_a = '88dc03f0-23fb-4f05-b462-e29186542864',
+    storage_2_1_b = '4230b711-f5c4-4131-bf98-88cd43a16901',
+    storage_2_2_a = '6b1eefbc-1e2e-410e-84ff-44c572ea9916',
+    storage_2_2_b = 'be74419a-1e56-4ba4-97e9-6b18710f63c5',
+}
+
+rs_1_1 = 'dd208fb8-8b90-49bc-8393-6b3a99da7c52'
+rs_1_2 = 'af9cfe88-2091-4613-a877-a623776c5c0e'
+rs_2_1 = '9ca8ee15-ae18-4f31-9385-4859f89ce73f'
+rs_2_2 = '007f5f58-b654-4125-8441-a71866fb62b5'
+
+local cfg_1 = {}
+cfg_1.sharding = {
+    [rs_1_1] = {
+        replicas = {
+            [names.storage_1_1_a] = {
+                uri = 'storage:storage@127.0.0.1:3301',
+                name = 'storage_1_1_a',
+                master = true,
+            },
+            [names.storage_1_1_b] = {
+                uri = 'storage:storage@127.0.0.1:3302',
+                name = 'storage_1_1_b',
+            },
+        }
+    },
+    [rs_1_2] = {
+        replicas = {
+            [names.storage_1_2_a] = {
+                uri = 'storage:storage@127.0.0.1:3303',
+                name = 'storage_1_2_a',
+                master = true,
+            },
+            [names.storage_1_2_b] = {
+                uri = 'storage:storage@127.0.0.1:3304',
+                name = 'storage_1_2_b',
+            },
+        }
+    },
+}
+
+
+local cfg_2 = {}
+cfg_2.sharding = {
+    [rs_2_1] = {
+        replicas = {
+            [names.storage_2_1_a] = {
+                uri = 'storage:storage@127.0.0.1:3305',
+                name = 'storage_2_1_a',
+                master = true,
+            },
+            [names.storage_2_1_b] = {
+                uri = 'storage:storage@127.0.0.1:3306',
+                name = 'storage_2_1_b',
+            },
+        }
+    },
+    [rs_2_2] = {
+        replicas = {
+            [names.storage_2_2_a] = {
+                uri = 'storage:storage@127.0.0.1:3307',
+                name = 'storage_2_2_a',
+                master = true,
+            },
+            [names.storage_2_2_b] = {
+                uri = 'storage:storage@127.0.0.1:3308',
+                name = 'storage_2_2_b',
+            },
+        }
+    },
+}
+
+return {
+    cfg_1 = cfg_1,
+    cfg_2 = cfg_2,
+}
diff --git a/test/multiple_routers/multiple_routers.result 
b/test/multiple_routers/multiple_routers.result
new file mode 100644
index 0000000..5b85e1c
--- /dev/null
+++ b/test/multiple_routers/multiple_routers.result
@@ -0,0 +1,301 @@
+test_run = require('test_run').new()
+---
+...
+REPLICASET_1_1 = { 'storage_1_1_a', 'storage_1_1_b' }
+---
+...
+REPLICASET_1_2 = { 'storage_1_2_a', 'storage_1_2_b' }
+---
+...
+REPLICASET_2_1 = { 'storage_2_1_a', 'storage_2_1_b' }
+---
+...
+REPLICASET_2_2 = { 'storage_2_2_a', 'storage_2_2_b' }
+---
+...
+test_run:create_cluster(REPLICASET_1_1, 'multiple_routers')
+---
+...
+test_run:create_cluster(REPLICASET_1_2, 'multiple_routers')
+---
+...
+test_run:create_cluster(REPLICASET_2_1, 'multiple_routers')
+---
+...
+test_run:create_cluster(REPLICASET_2_2, 'multiple_routers')
+---
+...
+util = require('lua_libs.util')
+---
+...
+util.wait_master(test_run, REPLICASET_1_1, 'storage_1_1_a')
+---
+...
+util.wait_master(test_run, REPLICASET_1_2, 'storage_1_2_a')
+---
+...
+util.wait_master(test_run, REPLICASET_2_1, 'storage_2_1_a')
+---
+...
+util.wait_master(test_run, REPLICASET_2_2, 'storage_2_2_a')
+---
+...
+test_run:cmd("create server router_1 with 
script='multiple_routers/router_1.lua'")
+---
+- true
+...
+test_run:cmd("start server router_1")
+---
+- true
+...
+-- Configure default (static) router.
+_ = test_run:cmd("switch router_1")
+---
+...
+vshard.router.cfg(configs.cfg_1)
+---
+...
+vshard.router.bootstrap()
+---
+- true
+...
+_ = test_run:cmd("switch storage_1_2_a")
+---
+...
+wait_rebalancer_state('The cluster is balanced ok', test_run)
+---
+...
+_ = test_run:cmd("switch router_1")
+---
+...
+vshard.router.call(1, 'write', 'do_replace', {{1, 1}})
+---
+- true
+...
+vshard.router.call(1, 'read', 'do_select', {1})
+---
+- [[1, 1]]
+...
+-- Test that static router is just a router object under the hood.
+static_router = vshard.router.internal.static_router
+---
+...
+static_router:route(1) == vshard.router.route(1)
+---
+- true
+...
+-- Configure extra router.
+router_2 = vshard.router.new('router_2', configs.cfg_2)
+---
+...
+router_2:bootstrap()
+---
+- true
+...
+_ = test_run:cmd("switch storage_2_2_a")
+---
+...
+wait_rebalancer_state('The cluster is balanced ok', test_run)
+---
+...
+_ = test_run:cmd("switch router_1")
+---
+...
+router_2:call(1, 'write', 'do_replace', {{2, 2}})
+---
+- true
+...
+router_2:call(1, 'read', 'do_select', {2})
+---
+- [[2, 2]]
+...
+-- Check that router_2 and static router serves different clusters.
+#router_2:call(1, 'read', 'do_select', {1}) == 0
+---
+- true
+...
+-- Create several routers to the same cluster.
+routers = {}
+---
+...
+for i = 3, 10 do routers[i] = vshard.router.new('router_' .. i, 
configs.cfg_2) end
+---
+...
+routers[3]:call(1, 'read', 'do_select', {2})
+---
+- [[2, 2]]
+...
+-- Check that they have their own background fibers.
+fiber_names = {}
+---
+...
+for i = 2, 10 do fiber_names['vshard.failover.router_' .. i] = true; 
fiber_names['vshard.discovery.router_' .. i] = true; end
+---
+...
+next(fiber_names) ~= nil
+---
+- true
+...
+fiber = require('fiber')
+---
+...
+for _, xfiber in pairs(fiber.info()) do fiber_names[xfiber.name] = nil end
+---
+...
+next(fiber_names) == nil
+---
+- true
+...
+-- Reconfigure one of routers do not affect the others.
+routers[3]:cfg(configs.cfg_1)
+---
+...
+routers[3]:call(1, 'read', 'do_select', {1})
+---
+- [[1, 1]]
+...
+#routers[3]:call(1, 'read', 'do_select', {2}) == 0
+---
+- true
+...
+#routers[4]:call(1, 'read', 'do_select', {1}) == 0
+---
+- true
+...
+routers[4]:call(1, 'read', 'do_select', {2})
+---
+- [[2, 2]]
+...
+routers[3]:cfg(configs.cfg_2)
+---
+...
+-- Try to create router with the same name.
+util = require('lua_libs.util')
+---
+...
+util.check_error(vshard.router.new, 'router_2', configs.cfg_2)
+---
+- null
+- type: ShardingError
+  code: 21
+  name: ROUTER_ALREADY_EXISTS
+  message: Router with name router_2 already exists
+...
+-- Reload router module.
+_, old_rs_1 = next(vshard.router.internal.static_router.replicasets)
+---
+...
+_, old_rs_2 = next(router_2.replicasets)
+---
+...
+package.loaded['vshard.router'] = nil
+---
+...
+vshard.router = require('vshard.router')
+---
+...
+while not old_rs_1.is_outdated do fiber.sleep(0.01) end
+---
+...
+while not old_rs_2.is_outdated do fiber.sleep(0.01) end
+---
+...
+vshard.router.call(1, 'read', 'do_select', {1})
+---
+- [[1, 1]]
+...
+router_2:call(1, 'read', 'do_select', {2})
+---
+- [[2, 2]]
+...
+routers[5]:call(1, 'read', 'do_select', {2})
+---
+- [[2, 2]]
+...
+-- Check lua_gc counter.
+lua_gc = require('vshard.lua_gc')
+---
+...
+vshard.router.internal.collect_lua_garbage_cnt == 0
+---
+- true
+...
+lua_gc.internal.bg_fiber == nil
+---
+- true
+...
+configs.cfg_2.collect_lua_garbage = true
+---
+...
+routers[5]:cfg(configs.cfg_2)
+---
+...
+lua_gc.internal.bg_fiber ~= nil
+---
+- true
+...
+routers[7]:cfg(configs.cfg_2)
+---
+...
+lua_gc.internal.bg_fiber ~= nil
+---
+- true
+...
+vshard.router.internal.collect_lua_garbage_cnt == 2
+---
+- true
+...
+package.loaded['vshard.router'] = nil
+---
+...
+vshard.router = require('vshard.router')
+---
+...
+vshard.router.internal.collect_lua_garbage_cnt == 2
+---
+- true
+...
+configs.cfg_2.collect_lua_garbage = nil
+---
+...
+routers[5]:cfg(configs.cfg_2)
+---
+...
+lua_gc.internal.bg_fiber ~= nil
+---
+- true
+...
+routers[7]:cfg(configs.cfg_2)
+---
+...
+vshard.router.internal.collect_lua_garbage_cnt == 0
+---
+- true
+...
+lua_gc.internal.bg_fiber == nil
+---
+- true
+...
+_ = test_run:cmd("switch default")
+---
+...
+test_run:cmd("stop server router_1")
+---
+- true
+...
+test_run:cmd("cleanup server router_1")
+---
+- true
+...
+test_run:drop_cluster(REPLICASET_1_1)
+---
+...
+test_run:drop_cluster(REPLICASET_1_2)
+---
+...
+test_run:drop_cluster(REPLICASET_2_1)
+---
+...
+test_run:drop_cluster(REPLICASET_2_2)
+---
+...
diff --git a/test/multiple_routers/multiple_routers.test.lua 
b/test/multiple_routers/multiple_routers.test.lua
new file mode 100644
index 0000000..ec3c7f7
--- /dev/null
+++ b/test/multiple_routers/multiple_routers.test.lua
@@ -0,0 +1,109 @@
+test_run = require('test_run').new()
+
+REPLICASET_1_1 = { 'storage_1_1_a', 'storage_1_1_b' }
+REPLICASET_1_2 = { 'storage_1_2_a', 'storage_1_2_b' }
+REPLICASET_2_1 = { 'storage_2_1_a', 'storage_2_1_b' }
+REPLICASET_2_2 = { 'storage_2_2_a', 'storage_2_2_b' }
+
+test_run:create_cluster(REPLICASET_1_1, 'multiple_routers')
+test_run:create_cluster(REPLICASET_1_2, 'multiple_routers')
+test_run:create_cluster(REPLICASET_2_1, 'multiple_routers')
+test_run:create_cluster(REPLICASET_2_2, 'multiple_routers')
+util = require('lua_libs.util')
+util.wait_master(test_run, REPLICASET_1_1, 'storage_1_1_a')
+util.wait_master(test_run, REPLICASET_1_2, 'storage_1_2_a')
+util.wait_master(test_run, REPLICASET_2_1, 'storage_2_1_a')
+util.wait_master(test_run, REPLICASET_2_2, 'storage_2_2_a')
+
+test_run:cmd("create server router_1 with 
script='multiple_routers/router_1.lua'")
+test_run:cmd("start server router_1")
+
+-- Configure default (static) router.
+_ = test_run:cmd("switch router_1")
+vshard.router.cfg(configs.cfg_1)
+vshard.router.bootstrap()
+_ = test_run:cmd("switch storage_1_2_a")
+wait_rebalancer_state('The cluster is balanced ok', test_run)
+_ = test_run:cmd("switch router_1")
+
+vshard.router.call(1, 'write', 'do_replace', {{1, 1}})
+vshard.router.call(1, 'read', 'do_select', {1})
+
+-- Test that static router is just a router object under the hood.
+static_router = vshard.router.internal.static_router
+static_router:route(1) == vshard.router.route(1)
+
+-- Configure extra router.
+router_2 = vshard.router.new('router_2', configs.cfg_2)
+router_2:bootstrap()
+_ = test_run:cmd("switch storage_2_2_a")
+wait_rebalancer_state('The cluster is balanced ok', test_run)
+_ = test_run:cmd("switch router_1")
+
+router_2:call(1, 'write', 'do_replace', {{2, 2}})
+router_2:call(1, 'read', 'do_select', {2})
+-- Check that router_2 and static router serves different clusters.
+#router_2:call(1, 'read', 'do_select', {1}) == 0
+
+-- Create several routers to the same cluster.
+routers = {}
+for i = 3, 10 do routers[i] = vshard.router.new('router_' .. i, 
configs.cfg_2) end
+routers[3]:call(1, 'read', 'do_select', {2})
+-- Check that they have their own background fibers.
+fiber_names = {}
+for i = 2, 10 do fiber_names['vshard.failover.router_' .. i] = true; 
fiber_names['vshard.discovery.router_' .. i] = true; end
+next(fiber_names) ~= nil
+fiber = require('fiber')
+for _, xfiber in pairs(fiber.info()) do fiber_names[xfiber.name] = nil end
+next(fiber_names) == nil
+
+-- Reconfigure one of routers do not affect the others.
+routers[3]:cfg(configs.cfg_1)
+routers[3]:call(1, 'read', 'do_select', {1})
+#routers[3]:call(1, 'read', 'do_select', {2}) == 0
+#routers[4]:call(1, 'read', 'do_select', {1}) == 0
+routers[4]:call(1, 'read', 'do_select', {2})
+routers[3]:cfg(configs.cfg_2)
+
+-- Try to create router with the same name.
+util = require('lua_libs.util')
+util.check_error(vshard.router.new, 'router_2', configs.cfg_2)
+
+-- Reload router module.
+_, old_rs_1 = next(vshard.router.internal.static_router.replicasets)
+_, old_rs_2 = next(router_2.replicasets)
+package.loaded['vshard.router'] = nil
+vshard.router = require('vshard.router')
+while not old_rs_1.is_outdated do fiber.sleep(0.01) end
+while not old_rs_2.is_outdated do fiber.sleep(0.01) end
+vshard.router.call(1, 'read', 'do_select', {1})
+router_2:call(1, 'read', 'do_select', {2})
+routers[5]:call(1, 'read', 'do_select', {2})
+
+-- Check lua_gc counter.
+lua_gc = require('vshard.lua_gc')
+vshard.router.internal.collect_lua_garbage_cnt == 0
+lua_gc.internal.bg_fiber == nil
+configs.cfg_2.collect_lua_garbage = true
+routers[5]:cfg(configs.cfg_2)
+lua_gc.internal.bg_fiber ~= nil
+routers[7]:cfg(configs.cfg_2)
+lua_gc.internal.bg_fiber ~= nil
+vshard.router.internal.collect_lua_garbage_cnt == 2
+package.loaded['vshard.router'] = nil
+vshard.router = require('vshard.router')
+vshard.router.internal.collect_lua_garbage_cnt == 2
+configs.cfg_2.collect_lua_garbage = nil
+routers[5]:cfg(configs.cfg_2)
+lua_gc.internal.bg_fiber ~= nil
+routers[7]:cfg(configs.cfg_2)
+vshard.router.internal.collect_lua_garbage_cnt == 0
+lua_gc.internal.bg_fiber == nil
+
+_ = test_run:cmd("switch default")
+test_run:cmd("stop server router_1")
+test_run:cmd("cleanup server router_1")
+test_run:drop_cluster(REPLICASET_1_1)
+test_run:drop_cluster(REPLICASET_1_2)
+test_run:drop_cluster(REPLICASET_2_1)
+test_run:drop_cluster(REPLICASET_2_2)
diff --git a/test/multiple_routers/router_1.lua 
b/test/multiple_routers/router_1.lua
new file mode 100644
index 0000000..2e9ea91
--- /dev/null
+++ b/test/multiple_routers/router_1.lua
@@ -0,0 +1,15 @@
+#!/usr/bin/env tarantool
+
+require('strict').on()
+
+-- Get instance name
+local fio = require('fio')
+local NAME = fio.basename(arg[0], '.lua')
+
+require('console').listen(os.getenv('ADMIN'))
+
+configs = require('configs')
+
+-- Start the database with sharding
+vshard = require('vshard')
+box.cfg{}
diff --git a/test/multiple_routers/storage_1_1_a.lua 
b/test/multiple_routers/storage_1_1_a.lua
new file mode 100644
index 0000000..b44a97a
--- /dev/null
+++ b/test/multiple_routers/storage_1_1_a.lua
@@ -0,0 +1,23 @@
+#!/usr/bin/env tarantool
+
+require('strict').on()
+
+-- Get instance name.
+local fio = require('fio')
+NAME = fio.basename(arg[0], '.lua')
+
+require('console').listen(os.getenv('ADMIN'))
+
+-- Fetch config for the cluster of the instance.
+if NAME:sub(9,9) == '1' then
+    cfg = require('configs').cfg_1
+else
+    cfg = require('configs').cfg_2
+end
+
+-- Start the database with sharding.
+vshard = require('vshard')
+vshard.storage.cfg(cfg, names[NAME])
+
+-- Bootstrap storage.
+require('lua_libs.bootstrap')
diff --git a/test/multiple_routers/storage_1_1_b.lua 
b/test/multiple_routers/storage_1_1_b.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_1_1_b.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_1_2_a.lua 
b/test/multiple_routers/storage_1_2_a.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_1_2_a.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_1_2_b.lua 
b/test/multiple_routers/storage_1_2_b.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_1_2_b.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_2_1_a.lua 
b/test/multiple_routers/storage_2_1_a.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_2_1_a.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_2_1_b.lua 
b/test/multiple_routers/storage_2_1_b.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_2_1_b.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_2_2_a.lua 
b/test/multiple_routers/storage_2_2_a.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_2_2_a.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/storage_2_2_b.lua 
b/test/multiple_routers/storage_2_2_b.lua
new file mode 120000
index 0000000..76d196b
--- /dev/null
+++ b/test/multiple_routers/storage_2_2_b.lua
@@ -0,0 +1 @@
+storage_1_1_a.lua
\ No newline at end of file
diff --git a/test/multiple_routers/suite.ini 
b/test/multiple_routers/suite.ini
new file mode 100644
index 0000000..d2d4470
--- /dev/null
+++ b/test/multiple_routers/suite.ini
@@ -0,0 +1,6 @@
+[default]
+core = tarantool
+description = Multiple routers tests
+script = test.lua
+is_parallel = False
+lua_libs = ../lua_libs configs.lua
diff --git a/test/multiple_routers/test.lua b/test/multiple_routers/test.lua
new file mode 100644
index 0000000..cb7c1ee
--- /dev/null
+++ b/test/multiple_routers/test.lua
@@ -0,0 +1,9 @@
+#!/usr/bin/env tarantool
+
+require('strict').on()
+
+box.cfg{
+    listen              = os.getenv("LISTEN"),
+}
+
+require('console').listen(os.getenv('ADMIN'))
diff --git a/test/router/exponential_timeout.result 
b/test/router/exponential_timeout.result
index fb54d0f..6748b64 100644
--- a/test/router/exponential_timeout.result
+++ b/test/router/exponential_timeout.result
@@ -37,10 +37,10 @@ test_run:cmd('switch router_1')
  util = require('util')
  ---
  ...
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  ---
  ...
  util.collect_timeouts(rs1)
diff --git a/test/router/exponential_timeout.test.lua 
b/test/router/exponential_timeout.test.lua
index 3ec0b8c..75d85bf 100644
--- a/test/router/exponential_timeout.test.lua
+++ b/test/router/exponential_timeout.test.lua
@@ -13,8 +13,8 @@ test_run:cmd("start server router_1")
  test_run:cmd('switch router_1')
  util = require('util')

-rs1 = vshard.router.internal.replicasets[replicasets[1]]
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]

  util.collect_timeouts(rs1)
  util.collect_timeouts(rs2)
diff --git a/test/router/reconnect_to_master.result 
b/test/router/reconnect_to_master.result
index 5e678ce..d502723 100644
--- a/test/router/reconnect_to_master.result
+++ b/test/router/reconnect_to_master.result
@@ -76,7 +76,7 @@ _ = test_run:cmd('stop server storage_1_a')
  _ = test_run:switch('router_1')
  ---
  ...
-reps = vshard.router.internal.replicasets
+reps = vshard.router.internal.static_router.replicasets
  ---
  ...
  test_run:cmd("setopt delimiter ';'")
@@ -95,7 +95,7 @@ end;
  ...
  function count_known_buckets()
      local known_buckets = 0
-    for _, id in pairs(vshard.router.internal.route_map) do
+    for _, id in pairs(vshard.router.internal.static_router.route_map) do
          known_buckets = known_buckets + 1
      end
      return known_buckets
@@ -127,7 +127,7 @@ is_disconnected()
  fiber = require('fiber')
  ---
  ...
-while vshard.router.internal.replicasets[replicasets[1]].replica == nil 
do fiber.sleep(0.1) end
+while 
vshard.router.internal.static_router.replicasets[replicasets[1]].replica 
== nil do fiber.sleep(0.1) end
  ---
  ...
  vshard.router.info()
diff --git a/test/router/reconnect_to_master.test.lua 
b/test/router/reconnect_to_master.test.lua
index 39ba90e..8820fa7 100644
--- a/test/router/reconnect_to_master.test.lua
+++ b/test/router/reconnect_to_master.test.lua
@@ -34,7 +34,7 @@ _ = test_run:cmd('stop server storage_1_a')

  _ = test_run:switch('router_1')

-reps = vshard.router.internal.replicasets
+reps = vshard.router.internal.static_router.replicasets
  test_run:cmd("setopt delimiter ';'")
  function is_disconnected()
      for i, rep in pairs(reps) do
@@ -46,7 +46,7 @@ function is_disconnected()
  end;
  function count_known_buckets()
      local known_buckets = 0
-    for _, id in pairs(vshard.router.internal.route_map) do
+    for _, id in pairs(vshard.router.internal.static_router.route_map) do
          known_buckets = known_buckets + 1
      end
      return known_buckets
@@ -63,7 +63,7 @@ is_disconnected()
  -- Wait until replica is connected to test alerts on unavailable
  -- master.
  fiber = require('fiber')
-while vshard.router.internal.replicasets[replicasets[1]].replica == nil 
do fiber.sleep(0.1) end
+while 
vshard.router.internal.static_router.replicasets[replicasets[1]].replica 
== nil do fiber.sleep(0.1) end
  vshard.router.info()

  -- Return master.
diff --git a/test/router/reload.result b/test/router/reload.result
index f0badc3..98e8e71 100644
--- a/test/router/reload.result
+++ b/test/router/reload.result
@@ -229,7 +229,7 @@ vshard.router.cfg(cfg)
  cfg.connection_outdate_delay = old_connection_delay
  ---
  ...
-vshard.router.internal.connection_outdate_delay = nil
+vshard.router.internal.static_router.connection_outdate_delay = nil
  ---
  ...
  rs_new = vshard.router.route(1)
diff --git a/test/router/reload.test.lua b/test/router/reload.test.lua
index 528222a..293cb26 100644
--- a/test/router/reload.test.lua
+++ b/test/router/reload.test.lua
@@ -104,7 +104,7 @@ old_connection_delay = cfg.connection_outdate_delay
  cfg.connection_outdate_delay = 0.3
  vshard.router.cfg(cfg)
  cfg.connection_outdate_delay = old_connection_delay
-vshard.router.internal.connection_outdate_delay = nil
+vshard.router.internal.static_router.connection_outdate_delay = nil
  rs_new = vshard.router.route(1)
  rs_old = rs
  _, replica_old = next(rs_old.replicas)
diff --git a/test/router/reroute_wrong_bucket.result 
b/test/router/reroute_wrong_bucket.result
index 7f2a494..989dc79 100644
--- a/test/router/reroute_wrong_bucket.result
+++ b/test/router/reroute_wrong_bucket.result
@@ -98,7 +98,7 @@ vshard.router.call(100, 'read', 'customer_lookup', 
{1}, {timeout = 100})
  ---
  - {'accounts': [], 'customer_id': 1, 'name': 'name'}
  ...
-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
  vshard.router.call(100, 'write', 'customer_add', {{customer_id = 2, 
bucket_id = 100, name = 'name2', accounts = {}}}, {timeout = 100})
@@ -146,13 +146,13 @@ test_run:switch('router_1')
  ...
  -- Emulate a situation, when a replicaset_2 while is unknown for
  -- router, but is already known for storages.
-save_rs2 = vshard.router.internal.replicasets[replicasets[2]]
+save_rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  ---
  ...
-vshard.router.internal.replicasets[replicasets[2]] = nil
+vshard.router.internal.static_router.replicasets[replicasets[2]] = nil
  ---
  ...
-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
  fiber = require('fiber')
@@ -207,7 +207,7 @@ err
  require('log').info(string.rep('a', 1000))
  ---
  ...
-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
  call_retval = nil
@@ -219,7 +219,7 @@ f = fiber.create(do_call, 100)
  while not test_run:grep_log('router_1', 'please update configuration', 
1000) do fiber.sleep(0.1) end
  ---
  ...
-vshard.router.internal.replicasets[replicasets[2]] = save_rs2
+vshard.router.internal.static_router.replicasets[replicasets[2]] = save_rs2
  ---
  ...
  while not call_retval do fiber.sleep(0.1) end
diff --git a/test/router/reroute_wrong_bucket.test.lua 
b/test/router/reroute_wrong_bucket.test.lua
index 03384d1..a00f941 100644
--- a/test/router/reroute_wrong_bucket.test.lua
+++ b/test/router/reroute_wrong_bucket.test.lua
@@ -35,7 +35,7 @@ customer_add({customer_id = 1, bucket_id = 100, name = 
'name', accounts = {}})
  test_run:switch('router_1')
  vshard.router.call(100, 'read', 'customer_lookup', {1}, {timeout = 100})

-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]
  vshard.router.call(100, 'write', 'customer_add', {{customer_id = 2, 
bucket_id = 100, name = 'name2', accounts = {}}}, {timeout = 100})

  -- Create cycle.
@@ -55,9 +55,9 @@ box.space._bucket:replace({100, 
vshard.consts.BUCKET.SENT, replicasets[2]})
  test_run:switch('router_1')
  -- Emulate a situation, when a replicaset_2 while is unknown for
  -- router, but is already known for storages.
-save_rs2 = vshard.router.internal.replicasets[replicasets[2]]
-vshard.router.internal.replicasets[replicasets[2]] = nil
-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+save_rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
+vshard.router.internal.static_router.replicasets[replicasets[2]] = nil
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]

  fiber = require('fiber')
  call_retval = nil
@@ -84,11 +84,11 @@ err
  -- detect it and end with ok.
  --
  require('log').info(string.rep('a', 1000))
-vshard.router.internal.route_map[100] = 
vshard.router.internal.replicasets[replicasets[1]]
+vshard.router.internal.static_router.route_map[100] = 
vshard.router.internal.static_router.replicasets[replicasets[1]]
  call_retval = nil
  f = fiber.create(do_call, 100)
  while not test_run:grep_log('router_1', 'please update configuration', 
1000) do fiber.sleep(0.1) end
-vshard.router.internal.replicasets[replicasets[2]] = save_rs2
+vshard.router.internal.static_router.replicasets[replicasets[2]] = save_rs2
  while not call_retval do fiber.sleep(0.1) end
  call_retval
  vshard.router.call(100, 'read', 'customer_lookup', {3}, {timeout = 1})
diff --git a/test/router/retry_reads.result b/test/router/retry_reads.result
index 64b0ff3..b803ae3 100644
--- a/test/router/retry_reads.result
+++ b/test/router/retry_reads.result
@@ -37,7 +37,7 @@ test_run:cmd('switch router_1')
  util = require('util')
  ---
  ...
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
  min_timeout = vshard.consts.CALL_TIMEOUT_MIN
diff --git a/test/router/retry_reads.test.lua 
b/test/router/retry_reads.test.lua
index 2fb2fc7..510e961 100644
--- a/test/router/retry_reads.test.lua
+++ b/test/router/retry_reads.test.lua
@@ -13,7 +13,7 @@ test_run:cmd("start server router_1")
  test_run:cmd('switch router_1')
  util = require('util')

-rs1 = vshard.router.internal.replicasets[replicasets[1]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
  min_timeout = vshard.consts.CALL_TIMEOUT_MIN

  --
diff --git a/test/router/router.result b/test/router/router.result
index 45394e1..ceaf672 100644
--- a/test/router/router.result
+++ b/test/router/router.result
@@ -70,10 +70,10 @@ test_run:grep_log('router_1', 'connected to ')
  ---
  - 'connected to '
  ...
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  ---
  ...
  fiber = require('fiber')
@@ -95,7 +95,7 @@ rs2.replica == rs2.master
  -- Part of gh-76: on reconfiguration do not recreate connections
  -- to replicas, that are kept in a new configuration.
  --
-old_replicasets = vshard.router.internal.replicasets
+old_replicasets = vshard.router.internal.static_router.replicasets
  ---
  ...
  old_connections = {}
@@ -127,17 +127,17 @@ connection_count == 4
  vshard.router.cfg(cfg)
  ---
  ...
-new_replicasets = vshard.router.internal.replicasets
+new_replicasets = vshard.router.internal.static_router.replicasets
  ---
  ...
  old_replicasets ~= new_replicasets
  ---
  - true
  ...
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  ---
  ...
  while not rs1.replica or not rs2.replica do fiber.sleep(0.1) end
@@ -225,7 +225,7 @@ vshard.router.bootstrap()
  --
  -- gh-108: negative bucket count on discovery.
  --
-vshard.router.internal.route_map = {}
+vshard.router.internal.static_router.route_map = {}
  ---
  ...
  rets = {}
@@ -456,7 +456,7 @@ conn.state
  rs_uuid = '<replicaset_2>'
  ---
  ...
-rs = vshard.router.internal.replicasets[rs_uuid]
+rs = vshard.router.internal.static_router.replicasets[rs_uuid]
  ---
  ...
  master = rs.master
@@ -605,7 +605,7 @@ vshard.router.info()
  ...
  -- Remove replica and master connections to trigger alert
  -- UNREACHABLE_REPLICASET.
-rs = vshard.router.internal.replicasets[replicasets[1]]
+rs = vshard.router.internal.static_router.replicasets[replicasets[1]]
  ---
  ...
  master_conn = rs.master.conn
@@ -749,7 +749,7 @@ test_run:cmd("setopt delimiter ';'")
  ...
  function calculate_known_buckets()
      local known_buckets = 0
-    for _, rs in pairs(vshard.router.internal.route_map) do
+    for _, rs in pairs(vshard.router.internal.static_router.route_map) do
          known_buckets = known_buckets + 1
      end
      return known_buckets
@@ -851,10 +851,10 @@ test_run:cmd("setopt delimiter ';'")
  - true
  ...
  for i = 1, 100 do
-    local rs = vshard.router.internal.route_map[i]
+    local rs = vshard.router.internal.static_router.route_map[i]
      assert(rs)
      rs.bucket_count = rs.bucket_count - 1
-    vshard.router.internal.route_map[i] = nil
+    vshard.router.internal.static_router.route_map[i] = nil
  end;
  ---
  ...
@@ -999,7 +999,7 @@ vshard.router.sync(100500)
  -- object method like this: object.method() instead of
  -- object:method(), an appropriate help-error returns.
  --
-_, replicaset = next(vshard.router.internal.replicasets)
+_, replicaset = next(vshard.router.internal.static_router.replicasets)
  ---
  ...
  error_messages = {}
@@ -1069,7 +1069,7 @@ test_run:cmd("setopt delimiter ';'")
  ---
  - true
  ...
-for bucket, rs in pairs(vshard.router.internal.route_map) do
+for bucket, rs in pairs(vshard.router.internal.static_router.route_map) do
      bucket_to_old_rs[bucket] = rs
      bucket_cnt = bucket_cnt + 1
  end;
@@ -1084,7 +1084,7 @@ vshard.router.cfg(cfg);
  ...
  for bucket, old_rs in pairs(bucket_to_old_rs) do
      local old_uuid = old_rs.uuid
-    local rs = vshard.router.internal.route_map[bucket]
+    local rs = vshard.router.internal.static_router.route_map[bucket]
      if not rs or not old_uuid == rs.uuid then
          error("Bucket lost during reconfigure.")
      end
@@ -1111,7 +1111,7 @@ end;
  vshard.router.cfg(cfg);
  ---
  ...
-vshard.router.internal.route_map = {};
+vshard.router.internal.static_router.route_map = {};
  ---
  ...
  vshard.router.internal.errinj.ERRINJ_LONG_DISCOVERY = false;
@@ -1119,7 +1119,7 @@ 
vshard.router.internal.errinj.ERRINJ_LONG_DISCOVERY = false;
  ...
  -- Do discovery iteration. Upload buckets from the
  -- first replicaset.
-while not next(vshard.router.internal.route_map) do
+while not next(vshard.router.internal.static_router.route_map) do
      vshard.router.discovery_wakeup()
      fiber.sleep(0.01)
  end;
@@ -1128,12 +1128,12 @@ end;
  new_replicasets = {};
  ---
  ...
-for _, rs in pairs(vshard.router.internal.replicasets) do
+for _, rs in pairs(vshard.router.internal.static_router.replicasets) do
      new_replicasets[rs] = true
  end;
  ---
  ...
-_, rs = next(vshard.router.internal.route_map);
+_, rs = next(vshard.router.internal.static_router.route_map);
  ---
  ...
  new_replicasets[rs] == true;
@@ -1185,6 +1185,17 @@ vshard.router.route(1):callro('echo', {'some_data'})
  - null
  - null
  ...
+-- Multiple routers: check that static router can be used as an
+-- object.
+static_router = vshard.router.internal.static_router
+---
+...
+static_router:route(1):callro('echo', {'some_data'})
+---
+- some_data
+- null
+- null
+...
  _ = test_run:cmd("switch default")
  ---
  ...
diff --git a/test/router/router.test.lua b/test/router/router.test.lua
index df2f381..d7588f7 100644
--- a/test/router/router.test.lua
+++ b/test/router/router.test.lua
@@ -27,8 +27,8 @@ util = require('util')

  -- gh-24: log all connnect/disconnect events.
  test_run:grep_log('router_1', 'connected to ')
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  fiber = require('fiber')
  while not rs1.replica or not rs2.replica do fiber.sleep(0.1) end
  -- With no zones the nearest server is master.
@@ -39,7 +39,7 @@ rs2.replica == rs2.master
  -- Part of gh-76: on reconfiguration do not recreate connections
  -- to replicas, that are kept in a new configuration.
  --
-old_replicasets = vshard.router.internal.replicasets
+old_replicasets = vshard.router.internal.static_router.replicasets
  old_connections = {}
  connection_count = 0
  test_run:cmd("setopt delimiter ';'")
@@ -52,10 +52,10 @@ end;
  test_run:cmd("setopt delimiter ''");
  connection_count == 4
  vshard.router.cfg(cfg)
-new_replicasets = vshard.router.internal.replicasets
+new_replicasets = vshard.router.internal.static_router.replicasets
  old_replicasets ~= new_replicasets
-rs1 = vshard.router.internal.replicasets[replicasets[1]]
-rs2 = vshard.router.internal.replicasets[replicasets[2]]
+rs1 = vshard.router.internal.static_router.replicasets[replicasets[1]]
+rs2 = vshard.router.internal.static_router.replicasets[replicasets[2]]
  while not rs1.replica or not rs2.replica do fiber.sleep(0.1) end
  vshard.router.discovery_wakeup()
  -- Check that netbox connections are the same.
@@ -91,7 +91,7 @@ vshard.router.bootstrap()
  --
  -- gh-108: negative bucket count on discovery.
  --
-vshard.router.internal.route_map = {}
+vshard.router.internal.static_router.route_map = {}
  rets = {}
  function do_echo() table.insert(rets, vshard.router.callro(1, 'echo', 
{1})) end
  f1 = fiber.create(do_echo) f2 = fiber.create(do_echo)
@@ -153,7 +153,7 @@ conn = vshard.router.route(1).master.conn
  conn.state
  -- Test missing master.
  rs_uuid = 'ac522f65-aa94-4134-9f64-51ee384f1a54'
-rs = vshard.router.internal.replicasets[rs_uuid]
+rs = vshard.router.internal.static_router.replicasets[rs_uuid]
  master = rs.master
  rs.master = nil
  vshard.router.route(1).master
@@ -223,7 +223,7 @@ vshard.router.info()

  -- Remove replica and master connections to trigger alert
  -- UNREACHABLE_REPLICASET.
-rs = vshard.router.internal.replicasets[replicasets[1]]
+rs = vshard.router.internal.static_router.replicasets[replicasets[1]]
  master_conn = rs.master.conn
  replica_conn = rs.replica.conn
  rs.master.conn = nil
@@ -261,7 +261,7 @@ util.check_error(vshard.router.buckets_info, 123, '456')
  test_run:cmd("setopt delimiter ';'")
  function calculate_known_buckets()
      local known_buckets = 0
-    for _, rs in pairs(vshard.router.internal.route_map) do
+    for _, rs in pairs(vshard.router.internal.static_router.route_map) do
          known_buckets = known_buckets + 1
      end
      return known_buckets
@@ -301,10 +301,10 @@ test_run:switch('router_1')
  --
  test_run:cmd("setopt delimiter ';'")
  for i = 1, 100 do
-    local rs = vshard.router.internal.route_map[i]
+    local rs = vshard.router.internal.static_router.route_map[i]
      assert(rs)
      rs.bucket_count = rs.bucket_count - 1
-    vshard.router.internal.route_map[i] = nil
+    vshard.router.internal.static_router.route_map[i] = nil
  end;
  test_run:cmd("setopt delimiter ''");
  calculate_known_buckets()
@@ -367,7 +367,7 @@ vshard.router.sync(100500)
  -- object method like this: object.method() instead of
  -- object:method(), an appropriate help-error returns.
  --
-_, replicaset = next(vshard.router.internal.replicasets)
+_, replicaset = next(vshard.router.internal.static_router.replicasets)
  error_messages = {}

  test_run:cmd("setopt delimiter ';'")
@@ -395,7 +395,7 @@ error_messages
  bucket_to_old_rs = {}
  bucket_cnt = 0
  test_run:cmd("setopt delimiter ';'")
-for bucket, rs in pairs(vshard.router.internal.route_map) do
+for bucket, rs in pairs(vshard.router.internal.static_router.route_map) do
      bucket_to_old_rs[bucket] = rs
      bucket_cnt = bucket_cnt + 1
  end;
@@ -403,7 +403,7 @@ bucket_cnt;
  vshard.router.cfg(cfg);
  for bucket, old_rs in pairs(bucket_to_old_rs) do
      local old_uuid = old_rs.uuid
-    local rs = vshard.router.internal.route_map[bucket]
+    local rs = vshard.router.internal.static_router.route_map[bucket]
      if not rs or not old_uuid == rs.uuid then
          error("Bucket lost during reconfigure.")
      end
@@ -423,19 +423,19 @@ while 
vshard.router.internal.errinj.ERRINJ_LONG_DISCOVERY ~= 'waiting' do
      fiber.sleep(0.02)
  end;
  vshard.router.cfg(cfg);
-vshard.router.internal.route_map = {};
+vshard.router.internal.static_router.route_map = {};
  vshard.router.internal.errinj.ERRINJ_LONG_DISCOVERY = false;
  -- Do discovery iteration. Upload buckets from the
  -- first replicaset.
-while not next(vshard.router.internal.route_map) do
+while not next(vshard.router.internal.static_router.route_map) do
      vshard.router.discovery_wakeup()
      fiber.sleep(0.01)
  end;
  new_replicasets = {};
-for _, rs in pairs(vshard.router.internal.replicasets) do
+for _, rs in pairs(vshard.router.internal.static_router.replicasets) do
      new_replicasets[rs] = true
  end;
-_, rs = next(vshard.router.internal.route_map);
+_, rs = next(vshard.router.internal.static_router.route_map);
  new_replicasets[rs] == true;
  test_run:cmd("setopt delimiter ''");

@@ -453,6 +453,11 @@ vshard.router.internal.errinj.ERRINJ_CFG = false
  util.has_same_fields(old_internal, vshard.router.internal)
  vshard.router.route(1):callro('echo', {'some_data'})

+-- Multiple routers: check that static router can be used as an
+-- object.
+static_router = vshard.router.internal.static_router
+static_router:route(1):callro('echo', {'some_data'})
+
  _ = test_run:cmd("switch default")
  test_run:drop_cluster(REPLICASET_2)

diff --git a/vshard/error.lua b/vshard/error.lua
index f79107b..da92b58 100644
--- a/vshard/error.lua
+++ b/vshard/error.lua
@@ -105,7 +105,12 @@ local error_message_template = {
          name = 'OBJECT_IS_OUTDATED',
          msg = 'Object is outdated after module reload/reconfigure. ' ..
                'Use new instance.'
-    }
+    },
+    [21] = {
+        name = 'ROUTER_ALREADY_EXISTS',
+        msg = 'Router with name %s already exists',
+        args = {'name'},
+    },
  }

  --
diff --git a/vshard/router/init.lua b/vshard/router/init.lua
index 59c25a0..b31f7dc 100644
--- a/vshard/router/init.lua
+++ b/vshard/router/init.lua
@@ -25,14 +25,33 @@ local M = rawget(_G, MODULE_INTERNALS)
  if not M then
      M = {
          ---------------- Common module attributes ----------------
-        -- The last passed configuration.
-        current_cfg = nil,
          errinj = {
              ERRINJ_CFG = false,
              ERRINJ_FAILOVER_CHANGE_CFG = false,
              ERRINJ_RELOAD = false,
              ERRINJ_LONG_DISCOVERY = false,
          },
+        -- Dictionary, key is router name, value is a router.
+        routers = {},
+        -- Router object which can be accessed by old api:
+        -- e.g. vshard.router.call(...)
+        static_router = nil,
+        -- This counter is used to restart background fibers with
+        -- new reloaded code.
+        module_version = 0,
+        -- Number of router which require collecting lua garbage.
+        collect_lua_garbage_cnt = 0,
+    }
+end
+
+--
+-- Router object attributes.
+--
+local ROUTER_TEMPLATE = {
+        -- Name of router.
+        name = nil,
+        -- The last passed configuration.
+        current_cfg = nil,
          -- Time to outdate old objects on reload.
          connection_outdate_delay = nil,
          -- Bucket map cache.
@@ -47,38 +66,60 @@ if not M then
          total_bucket_count = 0,
          -- Boolean lua_gc state (create periodic gc task).
          collect_lua_garbage = nil,
-        -- This counter is used to restart background fibers with
-        -- new reloaded code.
-        module_version = 0,
-    }
-end
+}
+
+local STATIC_ROUTER_NAME = '_static_router'

  -- Set a bucket to a replicaset.
-local function bucket_set(bucket_id, rs_uuid)
-    local replicaset = M.replicasets[rs_uuid]
+local function bucket_set(router, bucket_id, rs_uuid)
+    local replicaset = router.replicasets[rs_uuid]
      -- It is technically possible to delete a replicaset at the
      -- same time when route to the bucket is discovered.
      if not replicaset then
          return nil, lerror.vshard(lerror.code.NO_ROUTE_TO_BUCKET, 
bucket_id)
      end
-    local old_replicaset = M.route_map[bucket_id]
+    local old_replicaset = router.route_map[bucket_id]
      if old_replicaset ~= replicaset then
          if old_replicaset then
              old_replicaset.bucket_count = old_replicaset.bucket_count - 1
          end
          replicaset.bucket_count = replicaset.bucket_count + 1
      end
-    M.route_map[bucket_id] = replicaset
+    router.route_map[bucket_id] = replicaset
      return replicaset
  end

  -- Remove a bucket from the cache.
-local function bucket_reset(bucket_id)
-    local replicaset = M.route_map[bucket_id]
+local function bucket_reset(router, bucket_id)
+    local replicaset = router.route_map[bucket_id]
      if replicaset then
          replicaset.bucket_count = replicaset.bucket_count - 1
      end
-    M.route_map[bucket_id] = nil
+    router.route_map[bucket_id] = nil
+end
+
+--------------------------------------------------------------------------------
+-- Helpers
+--------------------------------------------------------------------------------
+
+--
+-- Increase/decrease number of routers which require to collect
+-- a lua garbage and change state of the `lua_gc` fiber.
+--
+
+local function lua_gc_cnt_inc()
+    M.collect_lua_garbage_cnt = M.collect_lua_garbage_cnt + 1
+    if M.collect_lua_garbage_cnt == 1 then
+        lua_gc.set_state(true, consts.COLLECT_LUA_GARBAGE_INTERVAL)
+    end
+end
+
+local function lua_gc_cnt_dec()
+    M.collect_lua_garbage_cnt = M.collect_lua_garbage_cnt - 1
+    assert(M.collect_lua_garbage_cnt >= 0)
+    if M.collect_lua_garbage_cnt == 0 then
+        lua_gc.set_state(false, consts.COLLECT_LUA_GARBAGE_INTERVAL)
+    end
  end

  --------------------------------------------------------------------------------
@@ -86,8 +127,8 @@ end
  --------------------------------------------------------------------------------

  -- Search bucket in whole cluster
-local function bucket_discovery(bucket_id)
-    local replicaset = M.route_map[bucket_id]
+local function bucket_discovery(router, bucket_id)
+    local replicaset = router.route_map[bucket_id]
      if replicaset ~= nil then
          return replicaset
      end
@@ -95,11 +136,11 @@ local function bucket_discovery(bucket_id)
      log.verbose("Discovering bucket %d", bucket_id)
      local last_err = nil
      local unreachable_uuid = nil
-    for uuid, replicaset in pairs(M.replicasets) do
+    for uuid, replicaset in pairs(router.replicasets) do
          local _, err =
              replicaset:callrw('vshard.storage.bucket_stat', {bucket_id})
          if err == nil then
-            return bucket_set(bucket_id, replicaset.uuid)
+            return bucket_set(router, bucket_id, replicaset.uuid)
          elseif err.code ~= lerror.code.WRONG_BUCKET then
              last_err = err
              unreachable_uuid = uuid
@@ -128,14 +169,14 @@ local function bucket_discovery(bucket_id)
  end

  -- Resolve bucket id to replicaset uuid
-local function bucket_resolve(bucket_id)
+local function bucket_resolve(router, bucket_id)
      local replicaset, err
-    local replicaset = M.route_map[bucket_id]
+    local replicaset = router.route_map[bucket_id]
      if replicaset ~= nil then
          return replicaset
      end
      -- Replicaset removed from cluster, perform discovery
-    replicaset, err = bucket_discovery(bucket_id)
+    replicaset, err = bucket_discovery(router, bucket_id)
      if replicaset == nil then
          return nil, err
      end
@@ -146,14 +187,14 @@ end
  -- Background fiber to perform discovery. It periodically scans
  -- replicasets one by one and updates route_map.
  --
-local function discovery_f()
+local function discovery_f(router)
      local module_version = M.module_version
      while module_version == M.module_version do
-        while not next(M.replicasets) do
+        while not next(router.replicasets) do
              lfiber.sleep(consts.DISCOVERY_INTERVAL)
          end
-        local old_replicasets = M.replicasets
-        for rs_uuid, replicaset in pairs(M.replicasets) do
+        local old_replicasets = router.replicasets
+        for rs_uuid, replicaset in pairs(router.replicasets) do
              local active_buckets, err =
replicaset:callro('vshard.storage.buckets_discovery', {},
                                    {timeout = 2})
@@ -163,7 +204,7 @@ local function discovery_f()
              end
              -- Renew replicasets object captured by the for loop
              -- in case of reconfigure and reload events.
-            if M.replicasets ~= old_replicasets then
+            if router.replicasets ~= old_replicasets then
                  break
              end
              if not active_buckets then
@@ -176,11 +217,11 @@ local function discovery_f()
                  end
                  replicaset.bucket_count = #active_buckets
                  for _, bucket_id in pairs(active_buckets) do
-                    local old_rs = M.route_map[bucket_id]
+                    local old_rs = router.route_map[bucket_id]
                      if old_rs and old_rs ~= replicaset then
                          old_rs.bucket_count = old_rs.bucket_count - 1
                      end
-                    M.route_map[bucket_id] = replicaset
+                    router.route_map[bucket_id] = replicaset
                  end
              end
              lfiber.sleep(consts.DISCOVERY_INTERVAL)
@@ -191,9 +232,9 @@ end
  --
  -- Immediately wakeup discovery fiber if exists.
  --
-local function discovery_wakeup()
-    if M.discovery_fiber then
-        M.discovery_fiber:wakeup()
+local function discovery_wakeup(router)
+    if router.discovery_fiber then
+        router.discovery_fiber:wakeup()
      end
  end

@@ -205,7 +246,7 @@ end
  -- Function will restart operation after wrong bucket response until 
timeout
  -- is reached
  --
-local function router_call(bucket_id, mode, func, args, opts)
+local function router_call(router, bucket_id, mode, func, args, opts)
      if opts and (type(opts) ~= 'table' or
                   (opts.timeout and type(opts.timeout) ~= 'number')) then
          error('Usage: call(bucket_id, mode, func, args, opts)')
@@ -213,7 +254,7 @@ local function router_call(bucket_id, mode, func, 
args, opts)
      local timeout = opts and opts.timeout or consts.CALL_TIMEOUT_MIN
      local replicaset, err
      local tend = lfiber.time() + timeout
-    if bucket_id > M.total_bucket_count or bucket_id <= 0 then
+    if bucket_id > router.total_bucket_count or bucket_id <= 0 then
          error('Bucket is unreachable: bucket id is out of range')
      end
      local call
@@ -223,7 +264,7 @@ local function router_call(bucket_id, mode, func, 
args, opts)
          call = 'callrw'
      end
      repeat
-        replicaset, err = bucket_resolve(bucket_id)
+        replicaset, err = bucket_resolve(router, bucket_id)
          if replicaset then
  ::replicaset_is_found::
              local storage_call_status, call_status, call_error =
@@ -239,9 +280,9 @@ local function router_call(bucket_id, mode, func, 
args, opts)
              end
              err = call_status
              if err.code == lerror.code.WRONG_BUCKET then
-                bucket_reset(bucket_id)
+                bucket_reset(router, bucket_id)
                  if err.destination then
-                    replicaset = M.replicasets[err.destination]
+                    replicaset = router.replicasets[err.destination]
                      if not replicaset then
                          log.warn('Replicaset "%s" was not found, but 
received'..
                                   ' from storage as destination - 
please '..
@@ -253,13 +294,14 @@ local function router_call(bucket_id, mode, func, 
args, opts)
                          -- but already is executed on storages.
                          while lfiber.time() <= tend do
                              lfiber.sleep(0.05)
-                            replicaset = M.replicasets[err.destination]
+                            replicaset = 
router.replicasets[err.destination]
                              if replicaset then
                                  goto replicaset_is_found
                              end
                          end
                      else
-                        replicaset = bucket_set(bucket_id, replicaset.uuid)
+                        replicaset = bucket_set(router, bucket_id,
+                                                replicaset.uuid)
                          lfiber.yield()
                          -- Protect against infinite cycle in a
                          -- case of broken cluster, when a bucket
@@ -276,7 +318,7 @@ local function router_call(bucket_id, mode, func, 
args, opts)
                  -- is not timeout - these requests are repeated in
                  -- any case on client, if error.
                  assert(mode == 'write')
-                bucket_reset(bucket_id)
+                bucket_reset(router, bucket_id)
                  return nil, err
              elseif err.code == lerror.code.NON_MASTER then
                  -- Same, as above - do not wait and repeat.
@@ -302,12 +344,12 @@ end
  --
  -- Wrappers for router_call with preset mode.
  --
-local function router_callro(bucket_id, ...)
-    return router_call(bucket_id, 'read', ...)
+local function router_callro(router, bucket_id, ...)
+    return router_call(router, bucket_id, 'read', ...)
  end

-local function router_callrw(bucket_id, ...)
-    return router_call(bucket_id, 'write', ...)
+local function router_callrw(router, bucket_id, ...)
+    return router_call(router, bucket_id, 'write', ...)
  end

  --
@@ -315,27 +357,27 @@ end
  -- @param bucket_id Bucket identifier.
  -- @retval Netbox connection.
  --
-local function router_route(bucket_id)
+local function router_route(router, bucket_id)
      if type(bucket_id) ~= 'number' then
          error('Usage: router.route(bucket_id)')
      end
-    return bucket_resolve(bucket_id)
+    return bucket_resolve(router, bucket_id)
  end

  --
  -- Return map of all replicasets.
  -- @retval See self.replicasets map.
  --
-local function router_routeall()
-    return M.replicasets
+local function router_routeall(router)
+    return router.replicasets
  end

  --------------------------------------------------------------------------------
  -- Failover
  --------------------------------------------------------------------------------

-local function failover_ping_round()
-    for _, replicaset in pairs(M.replicasets) do
+local function failover_ping_round(router)
+    for _, replicaset in pairs(router.replicasets) do
          local replica = replicaset.replica
          if replica ~= nil and replica.conn ~= nil and
             replica.down_ts == nil then
@@ -378,10 +420,10 @@ end
  -- Collect UUIDs of replicasets, priority of whose replica
  -- connections must be updated.
  --
-local function failover_collect_to_update()
+local function failover_collect_to_update(router)
      local ts = lfiber.time()
      local uuid_to_update = {}
-    for uuid, rs in pairs(M.replicasets) do
+    for uuid, rs in pairs(router.replicasets) do
          if failover_need_down_priority(rs, ts) or
             failover_need_up_priority(rs, ts) then
              table.insert(uuid_to_update, uuid)
@@ -396,16 +438,16 @@ end
  -- disconnected replicas.
  -- @retval true A replica of an replicaset has been changed.
  --
-local function failover_step()
-    failover_ping_round()
-    local uuid_to_update = failover_collect_to_update()
+local function failover_step(router)
+    failover_ping_round(router)
+    local uuid_to_update = failover_collect_to_update(router)
      if #uuid_to_update == 0 then
          return false
      end
      local curr_ts = lfiber.time()
      local replica_is_changed = false
      for _, uuid in pairs(uuid_to_update) do
-        local rs = M.replicasets[uuid]
+        local rs = router.replicasets[uuid]
          if M.errinj.ERRINJ_FAILOVER_CHANGE_CFG then
              rs = nil
              M.errinj.ERRINJ_FAILOVER_CHANGE_CFG = false
@@ -447,7 +489,7 @@ end
  -- tries to reconnect to the best replica. When the connection is
  -- established, it replaces the original replica.
  --
-local function failover_f()
+local function failover_f(router)
      local module_version = M.module_version
      local min_timeout = math.min(consts.FAILOVER_UP_TIMEOUT,
                                   consts.FAILOVER_DOWN_TIMEOUT)
@@ -457,7 +499,7 @@ local function failover_f()
      local prev_was_ok = false
      while module_version == M.module_version do
  ::continue::
-        local ok, replica_is_changed = pcall(failover_step)
+        local ok, replica_is_changed = pcall(failover_step, router)
          if not ok then
              log.error('Error during failovering: %s',
                        lerror.make(replica_is_changed))
@@ -484,8 +526,8 @@ end
  -- Configuration
  --------------------------------------------------------------------------------

-local function router_cfg(cfg, is_reload)
-    cfg = lcfg.check(cfg, M.current_cfg)
+local function router_cfg(router, cfg, is_reload)
+    cfg = lcfg.check(cfg, router.current_cfg)
      local vshard_cfg, box_cfg = lcfg.split(cfg)
      if not M.replicasets then
          log.info('Starting router configuration')
@@ -511,41 +553,47 @@ local function router_cfg(cfg, is_reload)
      -- Move connections from an old configuration to a new one.
      -- It must be done with no yields to prevent usage both of not
      -- fully moved old replicasets, and not fully built new ones.
-    lreplicaset.rebind_replicasets(new_replicasets, M.replicasets)
+    lreplicaset.rebind_replicasets(new_replicasets, router.replicasets)
      -- Now the new replicasets are fully built. Can establish
      -- connections and yield.
      for _, replicaset in pairs(new_replicasets) do
          replicaset:connect_all()
      end
+    -- Change state of lua GC.
+    if vshard_cfg.collect_lua_garbage and not 
router.collect_lua_garbage then
+        lua_gc_cnt_inc()
+    elseif not vshard_cfg.collect_lua_garbage and
+       router.collect_lua_garbage then
+        lua_gc_cnt_dec()
+    end
      lreplicaset.wait_masters_connect(new_replicasets)
-    lreplicaset.outdate_replicasets(M.replicasets,
+    lreplicaset.outdate_replicasets(router.replicasets,
vshard_cfg.connection_outdate_delay)
-    M.connection_outdate_delay = vshard_cfg.connection_outdate_delay
-    M.total_bucket_count = total_bucket_count
-    M.collect_lua_garbage = vshard_cfg.collect_lua_garbage
-    M.current_cfg = cfg
-    M.replicasets = new_replicasets
-    for bucket, rs in pairs(M.route_map) do
-        M.route_map[bucket] = M.replicasets[rs.uuid]
-    end
-    if M.failover_fiber == nil then
-        M.failover_fiber = 
util.reloadable_fiber_create('vshard.failover', M,
- 'failover_f')
+    router.connection_outdate_delay = vshard_cfg.connection_outdate_delay
+    router.total_bucket_count = total_bucket_count
+    router.collect_lua_garbage = vshard_cfg.collect_lua_garbage
+    router.current_cfg = cfg
+    router.replicasets = new_replicasets
+    for bucket, rs in pairs(router.route_map) do
+        router.route_map[bucket] = router.replicasets[rs.uuid]
+    end
+    if router.failover_fiber == nil then
+        router.failover_fiber = util.reloadable_fiber_create(
+            'vshard.failover.' .. router.name, M, 'failover_f', router)
+    end
+    if router.discovery_fiber == nil then
+        router.discovery_fiber = util.reloadable_fiber_create(
+            'vshard.discovery.' .. router.name, M, 'discovery_f', router)
      end
-    if M.discovery_fiber == nil then
-        M.discovery_fiber = 
util.reloadable_fiber_create('vshard.discovery', M,
- 'discovery_f')
-    end
-    lua_gc.set_state(M.collect_lua_garbage, 
consts.COLLECT_LUA_GARBAGE_INTERVAL)
  end

  --------------------------------------------------------------------------------
  -- Bootstrap
  --------------------------------------------------------------------------------

-local function cluster_bootstrap()
+local function cluster_bootstrap(router)
      local replicasets = {}
-    for uuid, replicaset in pairs(M.replicasets) do
+    for uuid, replicaset in pairs(router.replicasets) do
          table.insert(replicasets, replicaset)
          local count, err = 
replicaset:callrw('vshard.storage.buckets_count',
                                               {})
@@ -556,9 +604,10 @@ local function cluster_bootstrap()
              return nil, lerror.vshard(lerror.code.NON_EMPTY)
          end
      end
-    lreplicaset.calculate_etalon_balance(M.replicasets, 
M.total_bucket_count)
+    lreplicaset.calculate_etalon_balance(router.replicasets,
+                                         router.total_bucket_count)
      local bucket_id = 1
-    for uuid, replicaset in pairs(M.replicasets) do
+    for uuid, replicaset in pairs(router.replicasets) do
          if replicaset.etalon_bucket_count > 0 then
              local ok, err =
replicaset:callrw('vshard.storage.bucket_force_create',
@@ -614,7 +663,7 @@ local function replicaset_instance_info(replicaset, 
name, alerts, errcolor,
      return info, consts.STATUS.GREEN
  end

-local function router_info()
+local function router_info(router)
      local state = {
          replicasets = {},
          bucket = {
@@ -628,7 +677,7 @@ local function router_info()
      }
      local bucket_info = state.bucket
      local known_bucket_count = 0
-    for rs_uuid, replicaset in pairs(M.replicasets) do
+    for rs_uuid, replicaset in pairs(router.replicasets) do
          -- Replicaset info parameters:
          -- * master instance info;
          -- * replica instance info;
@@ -716,7 +765,7 @@ local function router_info()
          -- If a bucket is unreachable, then replicaset is
          -- unreachable too and color already is red.
      end
-    bucket_info.unknown = M.total_bucket_count - known_bucket_count
+    bucket_info.unknown = router.total_bucket_count - known_bucket_count
      if bucket_info.unknown > 0 then
          state.status = math.max(state.status, consts.STATUS.YELLOW)
          table.insert(state.alerts, 
lerror.alert(lerror.code.UNKNOWN_BUCKETS,
@@ -733,13 +782,13 @@ end
  -- @param limit Maximal bucket count in output.
  -- @retval Map of type {bucket_id = 'unknown'/replicaset_uuid}.
  --
-local function router_buckets_info(offset, limit)
+local function router_buckets_info(router, offset, limit)
      if offset ~= nil and type(offset) ~= 'number' or
         limit ~= nil and type(limit) ~= 'number' then
          error('Usage: buckets_info(offset, limit)')
      end
      offset = offset or 0
-    limit = limit or M.total_bucket_count
+    limit = limit or router.total_bucket_count
      local ret = {}
      -- Use one string memory for all unknown buckets.
      local available_rw = 'available_rw'
@@ -748,9 +797,9 @@ local function router_buckets_info(offset, limit)
      local unreachable = 'unreachable'
      -- Collect limit.
      local first = math.max(1, offset + 1)
-    local last = math.min(offset + limit, M.total_bucket_count)
+    local last = math.min(offset + limit, router.total_bucket_count)
      for bucket_id = first, last do
-        local rs = M.route_map[bucket_id]
+        local rs = router.route_map[bucket_id]
          if rs then
              if rs.master and rs.master:is_connected() then
                  ret[bucket_id] = {uuid = rs.uuid, status = available_rw}
@@ -770,22 +819,22 @@ end
  -- Other
  --------------------------------------------------------------------------------

-local function router_bucket_id(key)
+local function router_bucket_id(router, key)
      if key == nil then
          error("Usage: vshard.router.bucket_id(key)")
      end
-    return lhash.key_hash(key) % M.total_bucket_count + 1
+    return lhash.key_hash(key) % router.total_bucket_count + 1
  end

-local function router_bucket_count()
-    return M.total_bucket_count
+local function router_bucket_count(router)
+    return router.total_bucket_count
  end

-local function router_sync(timeout)
+local function router_sync(router, timeout)
      if timeout ~= nil and type(timeout) ~= 'number' then
          error('Usage: vshard.router.sync([timeout: number])')
      end
-    for rs_uuid, replicaset in pairs(M.replicasets) do
+    for rs_uuid, replicaset in pairs(router.replicasets) do
          local status, err = replicaset:callrw('vshard.storage.sync', 
{timeout})
          if not status then
              -- Add information about replicaset
@@ -799,6 +848,90 @@ if M.errinj.ERRINJ_RELOAD then
      error('Error injection: reload')
  end

+--------------------------------------------------------------------------------
+-- Managing router instances
+--------------------------------------------------------------------------------
+
+local function cfg_reconfigure(router, cfg)
+    return router_cfg(router, cfg, false)
+end
+
+local router_mt = {
+    __index = {
+        cfg = cfg_reconfigure;
+        info = router_info;
+        buckets_info = router_buckets_info;
+        call = router_call;
+        callro = router_callro;
+        callrw = router_callrw;
+        route = router_route;
+        routeall = router_routeall;
+        bucket_id = router_bucket_id;
+        bucket_count = router_bucket_count;
+        sync = router_sync;
+        bootstrap = cluster_bootstrap;
+        bucket_discovery = bucket_discovery;
+        discovery_wakeup = discovery_wakeup;
+    }
+}
+
+-- Table which represents this module.
+local module = {}
+
+-- This metatable bypasses calls to a module to the static_router.
+local module_mt = {__index = {}}
+for method_name, method in pairs(router_mt.__index) do
+    module_mt.__index[method_name] = function(...)
+        return method(M.static_router, ...)
+    end
+end
+
+local function export_static_router_attributes()
+    setmetatable(module, module_mt)
+end
+
+--
+-- Create a new instance of router.
+-- @param name Name of a new router.
+-- @param cfg Configuration for `router_cfg`.
+-- @retval Router instance.
+-- @retval Nil and error object.
+--
+local function router_new(name, cfg)
+    if type(name) ~= 'string' or type(cfg) ~= 'table' then
+           error('Wrong argument type. Usage: vshard.router.new(name, 
cfg).')
+    end
+    if M.routers[name] then
+        return nil, lerror.vshard(lerror.code.ROUTER_ALREADY_EXISTS, name)
+    end
+    local router = table.deepcopy(ROUTER_TEMPLATE)
+    setmetatable(router, router_mt)
+    router.name = name
+    M.routers[name] = router
+    router_cfg(router, cfg)
+    return router
+end
+
+--
+-- Wrapper around a `router_new` API, which allow to use old
+-- static `vshard.router.cfg()` API.
+--
+local function legacy_cfg(cfg)
+    if M.static_router then
+        -- Reconfigure.
+        router_cfg(M.static_router, cfg, false)
+    else
+        -- Create new static instance.
+        local router, err = router_new(STATIC_ROUTER_NAME, cfg)
+        if router then
+            M.static_router = router
+            export_static_router_attributes()
+        else
+            return nil, err
+        end
+    end
+end
+
  --------------------------------------------------------------------------------
  -- Module definition
  --------------------------------------------------------------------------------
@@ -809,28 +942,23 @@ end
  if not rawget(_G, MODULE_INTERNALS) then
      rawset(_G, MODULE_INTERNALS, M)
  else
-    router_cfg(M.current_cfg, true)
+    for _, router in pairs(M.routers) do
+        router_cfg(router, router.current_cfg, true)
+        setmetatable(router, router_mt)
+    end
+    if M.static_router then
+        export_static_router_attributes()
+    end
      M.module_version = M.module_version + 1
  end

  M.discovery_f = discovery_f
  M.failover_f = failover_f
+M.router_mt = router_mt

-return {
-    cfg = function(cfg) return router_cfg(cfg, false) end;
-    info = router_info;
-    buckets_info = router_buckets_info;
-    call = router_call;
-    callro = router_callro;
-    callrw = router_callrw;
-    route = router_route;
-    routeall = router_routeall;
-    bucket_id = router_bucket_id;
-    bucket_count = router_bucket_count;
-    sync = router_sync;
-    bootstrap = cluster_bootstrap;
-    bucket_discovery = bucket_discovery;
-    discovery_wakeup = discovery_wakeup;
-    internal = M;
-    module_version = function() return M.module_version end;
-}
+module.cfg = legacy_cfg
+module.new = router_new
+module.internal = M
+module.module_version = function() return M.module_version end
+
+return module
diff --git a/vshard/storage/init.lua b/vshard/storage/init.lua
index 0593edf..63aa96f 100644
--- a/vshard/storage/init.lua
+++ b/vshard/storage/init.lua
@@ -1632,8 +1632,6 @@ local function storage_cfg(cfg, this_replica_uuid, 
is_reload)
      M.rebalancer_max_receiving = rebalancer_max_receiving
      M.shard_index = shard_index
      M.collect_bucket_garbage_interval = collect_bucket_garbage_interval
-    M.collect_lua_garbage = collect_lua_garbage
-    M.current_cfg = cfg
      M.collect_lua_garbage = vshard_cfg.collect_lua_garbage
      M.current_cfg = cfg

diff --git a/vshard/util.lua b/vshard/util.lua
index 37abe2b..3afaa61 100644
--- a/vshard/util.lua
+++ b/vshard/util.lua
@@ -38,11 +38,11 @@ end
  -- reload of that module.
  -- See description of parameters in `reloadable_fiber_create`.
  --
-local function reloadable_fiber_main_loop(module, func_name)
+local function reloadable_fiber_main_loop(module, func_name, data)
      log.info('%s has been started', func_name)
      local func = module[func_name]
  ::restart_loop::
-    local ok, err = pcall(func)
+    local ok, err = pcall(func, data)
      -- yield serves two purposes:
      --  * makes this fiber cancellable
      --  * prevents 100% cpu consumption
@@ -60,7 +60,7 @@ local function reloadable_fiber_main_loop(module, 
func_name)
      log.info('module is reloaded, restarting')
      -- luajit drops this frame if next function is called in
      -- return statement.
-    return M.reloadable_fiber_main_loop(module, func_name)
+    return M.reloadable_fiber_main_loop(module, func_name, data)
  end

  --
@@ -74,11 +74,13 @@ end
  -- @param module Module which can be reloaded.
  -- @param func_name Name of a function to be executed in the
  --        module.
+-- @param data Data to be passed to the specified function.
  -- @retval New fiber.
  --
-local function reloadable_fiber_create(fiber_name, module, func_name)
+local function reloadable_fiber_create(fiber_name, module, func_name, data)
      assert(type(fiber_name) == 'string')
-    local xfiber = fiber.create(reloadable_fiber_main_loop, module, 
func_name)
+    local xfiber = fiber.create(reloadable_fiber_main_loop, module, 
func_name,
+                                data)
      xfiber:name(fiber_name)
      return xfiber
  end

  reply	other threads:[~2018-08-07 13:18 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-31 16:25 [tarantool-patches] [PATCH 0/3] multiple routers AKhatskevich
2018-07-31 16:25 ` [tarantool-patches] [PATCH 1/3] Update only vshard part of a cfg on reload AKhatskevich
2018-08-01 18:43   ` [tarantool-patches] " Vladislav Shpilevoy
2018-08-03 20:03     ` Alex Khatskevich
2018-08-06 17:03       ` Vladislav Shpilevoy
2018-08-07 13:19         ` Alex Khatskevich
2018-08-08 11:17           ` Vladislav Shpilevoy
2018-07-31 16:25 ` [tarantool-patches] [PATCH 2/3] Move lua gc to a dedicated module AKhatskevich
2018-08-01 18:43   ` [tarantool-patches] " Vladislav Shpilevoy
2018-08-03 20:04     ` Alex Khatskevich
2018-08-06 17:03       ` Vladislav Shpilevoy
2018-08-08 11:17       ` Vladislav Shpilevoy
2018-07-31 16:25 ` [tarantool-patches] [PATCH 3/3] Introduce multiple routers feature AKhatskevich
2018-08-01 18:43   ` [tarantool-patches] " Vladislav Shpilevoy
2018-08-03 20:05     ` Alex Khatskevich
2018-08-06 17:03       ` Vladislav Shpilevoy
2018-08-07 13:18         ` Alex Khatskevich [this message]
2018-08-08 12:28           ` Vladislav Shpilevoy
2018-08-08 14:04             ` Alex Khatskevich
2018-08-08 15:37               ` Vladislav Shpilevoy
2018-08-01 14:30 ` [tarantool-patches] [PATCH] Check self arg passed for router objects AKhatskevich
2018-08-03 20:07 ` [tarantool-patches] [PATCH] Refactor config templates AKhatskevich
2018-08-06 15:49   ` [tarantool-patches] " Vladislav Shpilevoy

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