[tarantool-patches] [PATCH v2] xlog: add request details to panic message for broken LSN

Sergei Kalashnikov ztarvos at gmail.com
Mon Aug 27 14:22:24 MSK 2018


Aid the debugging of replication issues related to out-of-order
requests. Adds the details of request/tuple to the diagnostic
message whenever possible.

Closes #3105
---
https://github.com/tarantool/tarantool/issues/3105
https://github.com/tarantool/tarantool/commits/ztarvos/gh-3105-log-request-broken-lsn

 src/box/applier.cc                              |   6 +-
 src/box/recovery.cc                             |   4 +-
 src/box/relay.cc                                |   8 +
 src/box/vclock.c                                |   8 +-
 src/box/vclock.h                                |   8 +
 src/box/wal.c                                   |   8 +-
 src/box/xlog.c                                  |   8 +
 src/box/xrow.h                                  |  29 ++++
 src/errinj.h                                    |   2 +
 test/box/errinj.result                          |   4 +
 test/xlog/log_request_broken_lsn_panic.result   | 187 ++++++++++++++++++++++++
 test/xlog/log_request_broken_lsn_panic.test.lua |  78 ++++++++++
 test/xlog/panic_replica.lua                     |   9 ++
 test/xlog/suite.ini                             |   2 +-
 14 files changed, 342 insertions(+), 19 deletions(-)
 create mode 100644 test/xlog/log_request_broken_lsn_panic.result
 create mode 100644 test/xlog/log_request_broken_lsn_panic.test.lua
 create mode 100644 test/xlog/panic_replica.lua

diff --git a/src/box/applier.cc b/src/box/applier.cc
index dbb4d05..5d87867 100644
--- a/src/box/applier.cc
+++ b/src/box/applier.cc
@@ -336,8 +336,7 @@ applier_join(struct applier *applier)
 		coio_read_xrow(coio, ibuf, &row);
 		applier->last_row_time = ev_monotonic_now(loop());
 		if (iproto_type_is_dml(row.type)) {
-			vclock_follow(&replicaset.vclock, row.replica_id,
-				      row.lsn);
+			vclock_follow_xrow(&replicaset.vclock, &row);
 			xstream_write_xc(applier->subscribe_stream, &row);
 		} else if (row.type == IPROTO_OK) {
 			/*
@@ -503,8 +502,7 @@ applier_subscribe(struct applier *applier)
 			 * the row is skipped when the replication
 			 * is resumed.
 			 */
-			vclock_follow(&replicaset.vclock, row.replica_id,
-				      row.lsn);
+			vclock_follow_xrow(&replicaset.vclock, &row);
 			struct replica *replica = replica_by_id(row.replica_id);
 			struct latch *latch = (replica ? &replica->order_latch :
 					       &replicaset.applier.order_latch);
diff --git a/src/box/recovery.cc b/src/box/recovery.cc
index fe14def..77357f0 100644
--- a/src/box/recovery.cc
+++ b/src/box/recovery.cc
@@ -135,7 +135,7 @@ recovery_scan(struct recovery *r, struct vclock *end_vclock)
 		return;
 	struct xrow_header row;
 	while (xlog_cursor_next(&cursor, &row, true) == 0)
-		vclock_follow(end_vclock, row.replica_id, row.lsn);
+		vclock_follow_xrow(end_vclock, &row);
 	xlog_cursor_close(&cursor, false);
 }
 
@@ -266,7 +266,7 @@ recover_xlog(struct recovery *r, struct xstream *stream,
 		 * in case of forced recovery, when we skip the
 		 * failed row anyway.
 		 */
-		vclock_follow(&r->vclock,  row.replica_id, row.lsn);
+		vclock_follow_xrow(&r->vclock, &row);
 		if (xstream_write(stream, &row) == 0) {
 			++row_count;
 			if (row_count % 100000 == 0)
diff --git a/src/box/relay.cc b/src/box/relay.cc
index 138e66d..2d0b651 100644
--- a/src/box/relay.cc
+++ b/src/box/relay.cc
@@ -678,4 +678,12 @@ relay_send_row(struct xstream *stream, struct xrow_header *packet)
 				      packet->replica_id)) {
 		relay_send(relay, packet);
 	}
+#ifndef NDEBUG
+	struct errinj *inj = errinj(ERRINJ_RELAY_BREAK_LSN, ERRINJ_INT);
+	if (inj != NULL && packet->lsn == inj->iparam) {
+		relay_send(relay, packet);
+		diag_set(ClientError, ER_INJECTION,
+			 "relay broken lsn injection lsn");
+	}
+#endif
 }
diff --git a/src/box/vclock.c b/src/box/vclock.c
index 2189ea8..b5eb280 100644
--- a/src/box/vclock.c
+++ b/src/box/vclock.c
@@ -42,13 +42,7 @@ vclock_follow(struct vclock *vclock, uint32_t replica_id, int64_t lsn)
 	assert(lsn >= 0);
 	assert(replica_id < VCLOCK_MAX);
 	int64_t prev_lsn = vclock->lsn[replica_id];
-	if (lsn <= prev_lsn) {
-		/* Never confirm LSN out of order. */
-		panic("LSN for %u is used twice or COMMIT order is broken: "
-		      "confirmed: %lld, new: %lld",
-		      (unsigned) replica_id,
-		      (long long) prev_lsn, (long long) lsn);
-	}
+	assert(lsn > prev_lsn);
 	/* Easier add each time than check. */
 	vclock->map |= 1 << replica_id;
 	vclock->lsn[replica_id] = lsn;
diff --git a/src/box/vclock.h b/src/box/vclock.h
index 928717c..111e291 100644
--- a/src/box/vclock.h
+++ b/src/box/vclock.h
@@ -199,6 +199,14 @@ vclock_sum(const struct vclock *vclock)
 	return vclock->signature;
 }
 
+/**
+ * Update vclock with the next LSN value for given replica id.
+ *
+ * @param vclock Vector clock.
+ * @param replica_id Replica identifier.
+ * @param lsn Next lsn.
+ * @return previous lsn value.
+ */
 int64_t
 vclock_follow(struct vclock *vclock, uint32_t replica_id, int64_t lsn);
 
diff --git a/src/box/wal.c b/src/box/wal.c
index cd068a4..9cc1901 100644
--- a/src/box/wal.c
+++ b/src/box/wal.c
@@ -652,8 +652,7 @@ wal_assign_lsn(struct wal_writer *writer, struct xrow_header **row,
 			(*row)->lsn = vclock_inc(&writer->vclock, instance_id);
 			(*row)->replica_id = instance_id;
 		} else {
-			vclock_follow(&writer->vclock, (*row)->replica_id,
-				      (*row)->lsn);
+			vclock_follow_xrow(&writer->vclock, *row);
 		}
 	}
 }
@@ -878,9 +877,8 @@ wal_write(struct journal *journal, struct journal_entry *entry)
 				 */
 				if (vclock_get(&replicaset.vclock,
 					       instance_id) < (*last)->lsn) {
-					vclock_follow(&replicaset.vclock,
-						      instance_id,
-						      (*last)->lsn);
+					vclock_follow_xrow(&replicaset.vclock,
+							   *last);
 				}
 				break;
 			}
diff --git a/src/box/xlog.c b/src/box/xlog.c
index d399a72..46cf7ed 100644
--- a/src/box/xlog.c
+++ b/src/box/xlog.c
@@ -1246,6 +1246,14 @@ xlog_write_row(struct xlog *log, const struct xrow_header *packet)
 	size_t page_offset = obuf_size(&log->obuf);
 	/** encode row into iovec */
 	struct iovec iov[XROW_IOVMAX];
+#ifndef NDEBUG
+	struct errinj *inj = errinj(ERRINJ_XLOG_BREAK_LSN, ERRINJ_INT);
+	if (inj != NULL && inj->iparam == packet->lsn) {
+		((struct xrow_header *)packet)->lsn = inj->iparam - 1;
+		diag_set(ClientError, ER_INJECTION,
+			 "xlog broken lsn injection lsn");
+	}
+#endif
 	/** don't write sync to the disk */
 	int iovcnt = xrow_header_encode(packet, 0, iov, 0);
 	if (iovcnt < 0) {
diff --git a/src/box/xrow.h b/src/box/xrow.h
index 4721670..f7eda91 100644
--- a/src/box/xrow.h
+++ b/src/box/xrow.h
@@ -522,6 +522,35 @@ xrow_to_iovec(const struct xrow_header *row, struct iovec *out);
 void
 xrow_decode_error(struct xrow_header *row);
 
+/**
+ * Update vclock with the next LSN value for given replica id.
+ * The function will cause panic if the next LSN happens to be
+ * out of order. The details of provided row are included into
+ * diagnostic message.
+ *
+ * @param vclock Vector clock.
+ * @param row Data row.
+ * @return Previous LSN value.
+ */
+static inline int64_t
+vclock_follow_xrow(struct vclock* vclock, const struct xrow_header *row)
+{
+	assert(row);
+	assert(row->replica_id < VCLOCK_MAX);
+	if (row->lsn <= vclock->lsn[row->replica_id]) {
+		struct request req;
+		xrow_decode_dml((struct xrow_header *)row, &req, 0);
+		/* Never confirm LSN out of order. */
+		panic("LSN for %u is used twice or COMMIT order is broken: "
+		      "confirmed: %lld, new: %lld, req: %s",
+		      (unsigned) row->replica_id,
+		      (long long) vclock->lsn[row->replica_id],
+		      (long long) row->lsn,
+		      request_str(&req));
+	}
+	return vclock_follow(vclock, row->replica_id, row->lsn);
+}
+
 #if defined(__cplusplus)
 } /* extern "C" */
 
diff --git a/src/errinj.h b/src/errinj.h
index 64d13b0..c658cd7 100644
--- a/src/errinj.h
+++ b/src/errinj.h
@@ -118,6 +118,8 @@ struct errinj {
 	_(ERRINJ_VY_LOG_FILE_RENAME, ERRINJ_BOOL, {.bparam = false}) \
 	_(ERRINJ_VY_RUN_FILE_RENAME, ERRINJ_BOOL, {.bparam = false}) \
 	_(ERRINJ_VY_INDEX_FILE_RENAME, ERRINJ_BOOL, {.bparam = false}) \
+	_(ERRINJ_RELAY_BREAK_LSN, ERRINJ_INT, {.iparam = -1}) \
+	_(ERRINJ_XLOG_BREAK_LSN, ERRINJ_INT, {.iparam = -1}) \
 
 ENUM0(errinj_id, ERRINJ_LIST);
 extern struct errinj errinjs[];
diff --git a/test/box/errinj.result b/test/box/errinj.result
index c7e4ce2..dca2c2d 100644
--- a/test/box/errinj.result
+++ b/test/box/errinj.result
@@ -16,6 +16,8 @@ errinj.info()
     state: 0
   ERRINJ_WAL_WRITE:
     state: false
+  ERRINJ_XLOG_BREAK_LSN:
+    state: -1
   ERRINJ_HTTPC_EXECUTE:
     state: false
   ERRINJ_VYRUN_DATA_READ:
@@ -60,6 +62,8 @@ errinj.info()
     state: false
   ERRINJ_WAL_WRITE_DISK:
     state: false
+  ERRINJ_RELAY_BREAK_LSN:
+    state: -1
   ERRINJ_VY_LOG_FILE_RENAME:
     state: false
   ERRINJ_VY_RUN_WRITE:
diff --git a/test/xlog/log_request_broken_lsn_panic.result b/test/xlog/log_request_broken_lsn_panic.result
new file mode 100644
index 0000000..2fd29c1
--- /dev/null
+++ b/test/xlog/log_request_broken_lsn_panic.result
@@ -0,0 +1,187 @@
+-- Issue 3105: Test logging of request with broken lsn before panicking
+-- Two cases are covered: Recovery and Initial Join
+env = require('test_run')
+---
+...
+test_run = env.new()
+---
+...
+fio = require('fio')
+---
+...
+test_run:cmd("setopt delimiter ';'")
+---
+- true
+...
+function grep_file_tail(filepath, bytes, pattern)
+    local fh = fio.open(filepath, {'O_RDONLY'})
+    local size = fh:seek(0, 'SEEK_END')
+    if size < bytes then
+        bytes = size
+    end
+    fh:seek(-bytes, 'SEEK_END')
+    local line = fh:read(bytes)
+    fh:close()
+    return string.match(line, pattern)
+end;
+---
+...
+test_run:cmd("setopt delimiter ''");
+---
+- true
+...
+-- Testing case of panic on recovery
+test_run:cmd('create server replica with script="xlog/panic_replica.lua"')
+---
+- true
+...
+test_run:cmd('start server replica')
+---
+- true
+...
+test_run:switch('replica')
+---
+- true
+...
+box.space._schema:replace{"t0", "v0"}
+---
+- ['t0', 'v0']
+...
+lsn = box.info.vclock[1]
+---
+...
+box.error.injection.set("ERRINJ_XLOG_BREAK_LSN", lsn + 1)
+---
+- ok
+...
+box.space._schema:replace{"t0", "v1"}
+---
+- ['t0', 'v1']
+...
+box.error.injection.set("ERRINJ_XLOG_BREAK_LSN", -1)
+---
+- ok
+...
+test_run:switch('default')
+---
+- true
+...
+test_run:cmd('stop server replica')
+---
+- true
+...
+dirname = fio.pathjoin(fio.cwd(), "panic_replica")
+---
+...
+xlogs = fio.glob(dirname .. "/*.xlog")
+---
+...
+fio.unlink(xlogs[#xlogs])
+---
+- true
+...
+test_run:cmd('start server replica with crash_expected=True')
+---
+- false
+...
+logpath = fio.pathjoin(fio.cwd(), 'panic_replica.log')
+---
+...
+-- Check that log contains the mention of broken LSN and the request printout
+grep_file_tail(logpath, 256, "LSN for 1 is used twice or COMMIT order is broken: confirmed: 1, new: 1, req: {.*}")
+---
+- 'LSN for 1 is used twice or COMMIT order is broken: confirmed: 1, new: 1, req: {type:
+  ''REPLACE'', lsn: 1, space_id: 272, index_id: 0, tuple: ["t0", "v1"]}'
+...
+test_run:cmd('cleanup server replica')
+---
+- true
+...
+test_run:cmd('delete server replica')
+---
+- true
+...
+-- Testing case of panic on initial join
+test_run:cmd('create server leader with script="xlog/replica.lua"')
+---
+- true
+...
+test_run:cmd("start server leader")
+---
+- true
+...
+test_run:switch('leader')
+---
+- true
+...
+box.schema.user.grant('guest', 'super')
+---
+...
+_ = box.schema.space.create('test')
+---
+...
+_ = box.space.test:create_index('pk')
+---
+...
+box.space.test:auto_increment{'v0'}
+---
+- [1, 'v0']
+...
+lsn = box.info.vclock[1]
+---
+...
+box.error.injection.set("ERRINJ_RELAY_BREAK_LSN", lsn + 1)
+---
+- ok
+...
+box.space.test:auto_increment{'v1'}
+---
+- [2, 'v1']
+...
+test_run:cmd('create server replica with rpl_master=leader, script="xlog/panic_replica.lua"')
+---
+- true
+...
+test_run:cmd('start server replica with crash_expected=True')
+---
+- false
+...
+fiber = require('fiber')
+---
+...
+while box.info.replication == nil do fiber.sleep(0.001) end
+---
+...
+while box.info.replication[2].downstream.status ~= "stopped" do fiber.sleep(0.001) end
+---
+...
+test_run:switch('default')
+---
+- true
+...
+-- Check that log contains the mention of broken LSN and the request printout
+grep_file_tail(logpath, 256, "LSN for 1 is used twice or COMMIT order is broken: confirmed: 6, new: 6, req: {.*}")
+---
+- 'LSN for 1 is used twice or COMMIT order is broken: confirmed: 6, new: 6, req: {type:
+  ''INSERT'', lsn: 6, space_id: 512, index_id: 0, tuple: [2, "v1"]}'
+...
+test_run:cmd('stop server leader')
+---
+- true
+...
+test_run:cmd('cleanup server leader')
+---
+- true
+...
+test_run:cmd('delete server leader')
+---
+- true
+...
+test_run:cmd('cleanup server replica')
+---
+- true
+...
+test_run:cmd('delete server replica')
+---
+- true
+...
diff --git a/test/xlog/log_request_broken_lsn_panic.test.lua b/test/xlog/log_request_broken_lsn_panic.test.lua
new file mode 100644
index 0000000..e0b3295
--- /dev/null
+++ b/test/xlog/log_request_broken_lsn_panic.test.lua
@@ -0,0 +1,78 @@
+-- Issue 3105: Test logging of request with broken lsn before panicking
+-- Two cases are covered: Recovery and Initial Join
+env = require('test_run')
+test_run = env.new()
+
+fio = require('fio')
+test_run:cmd("setopt delimiter ';'")
+function grep_file_tail(filepath, bytes, pattern)
+    local fh = fio.open(filepath, {'O_RDONLY'})
+    local size = fh:seek(0, 'SEEK_END')
+    if size < bytes then
+        bytes = size
+    end
+    fh:seek(-bytes, 'SEEK_END')
+    local line = fh:read(bytes)
+    fh:close()
+    return string.match(line, pattern)
+end;
+test_run:cmd("setopt delimiter ''");
+
+-- Testing case of panic on recovery
+test_run:cmd('create server replica with script="xlog/panic_replica.lua"')
+test_run:cmd('start server replica')
+test_run:switch('replica')
+
+box.space._schema:replace{"t0", "v0"}
+lsn = box.info.vclock[1]
+box.error.injection.set("ERRINJ_XLOG_BREAK_LSN", lsn + 1)
+box.space._schema:replace{"t0", "v1"}
+box.error.injection.set("ERRINJ_XLOG_BREAK_LSN", -1)
+
+test_run:switch('default')
+test_run:cmd('stop server replica')
+
+dirname = fio.pathjoin(fio.cwd(), "panic_replica")
+xlogs = fio.glob(dirname .. "/*.xlog")
+fio.unlink(xlogs[#xlogs])
+
+test_run:cmd('start server replica with crash_expected=True')
+
+logpath = fio.pathjoin(fio.cwd(), 'panic_replica.log')
+
+-- Check that log contains the mention of broken LSN and the request printout
+grep_file_tail(logpath, 256, "LSN for 1 is used twice or COMMIT order is broken: confirmed: 1, new: 1, req: {.*}")
+
+test_run:cmd('cleanup server replica')
+test_run:cmd('delete server replica')
+
+-- Testing case of panic on initial join
+test_run:cmd('create server leader with script="xlog/replica.lua"')
+test_run:cmd("start server leader")
+test_run:switch('leader')
+
+box.schema.user.grant('guest', 'super')
+_ = box.schema.space.create('test')
+_ = box.space.test:create_index('pk')
+
+box.space.test:auto_increment{'v0'}
+lsn = box.info.vclock[1]
+box.error.injection.set("ERRINJ_RELAY_BREAK_LSN", lsn + 1)
+box.space.test:auto_increment{'v1'}
+
+test_run:cmd('create server replica with rpl_master=leader, script="xlog/panic_replica.lua"')
+test_run:cmd('start server replica with crash_expected=True')
+fiber = require('fiber')
+while box.info.replication == nil do fiber.sleep(0.001) end
+while box.info.replication[2].downstream.status ~= "stopped" do fiber.sleep(0.001) end
+
+test_run:switch('default')
+-- Check that log contains the mention of broken LSN and the request printout
+grep_file_tail(logpath, 256, "LSN for 1 is used twice or COMMIT order is broken: confirmed: 6, new: 6, req: {.*}")
+
+test_run:cmd('stop server leader')
+test_run:cmd('cleanup server leader')
+test_run:cmd('delete server leader')
+
+test_run:cmd('cleanup server replica')
+test_run:cmd('delete server replica')
diff --git a/test/xlog/panic_replica.lua b/test/xlog/panic_replica.lua
new file mode 100644
index 0000000..ed0ba38
--- /dev/null
+++ b/test/xlog/panic_replica.lua
@@ -0,0 +1,9 @@
+#!/usr/bin/env tarantool
+
+box.cfg({
+    listen              = os.getenv("LISTEN"),
+    replication         = os.getenv("MASTER"),
+    memtx_memory        = 107374182,
+})
+
+require('console').listen(os.getenv('ADMIN'))
diff --git a/test/xlog/suite.ini b/test/xlog/suite.ini
index 8ee9720..f27b0f9 100644
--- a/test/xlog/suite.ini
+++ b/test/xlog/suite.ini
@@ -4,7 +4,7 @@ description = tarantool write ahead log tests
 script = xlog.lua
 disabled = snap_io_rate.test.lua
 valgrind_disabled =
-release_disabled = errinj.test.lua panic_on_lsn_gap.test.lua
+release_disabled = errinj.test.lua panic_on_lsn_gap.test.lua log_request_broken_lsn_panic.test.lua
 config = suite.cfg
 use_unix_sockets = True
 long_run = snap_io_rate.test.lua
-- 
1.8.3.1





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