[PATCH] vinyl: remove runs not referenced by any checkpoint immediately

[PATCH] vinyl: remove runs not referenced by any checkpoint immediately

[Vladimir Davydov]

If a compacted run was created after the last checkpoint, it is not
needed to recover from any checkpoint and hence can be deleted right
away to save disk space.

Closes #3407
---
https://github.com/tarantool/tarantool/issues/3407
https://github.com/tarantool/tarantool/commits/gh-3407-vy-remove-unreferenced-runs-immediately

 src/box/vy_scheduler.c | 27 +++++++++--------
 test/vinyl/gc.result   | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test/vinyl/gc.test.lua | 35 ++++++++++++++++++++++
 3 files changed, 126 insertions(+), 14 deletions(-)

diff --git a/src/box/vy_scheduler.c b/src/box/vy_scheduler.c
index e1853e5d..4c9103cf 100644
--- a/src/box/vy_scheduler.c
+++ b/src/box/vy_scheduler.c
@@ -1139,22 +1139,21 @@ vy_task_compact_complete(struct vy_scheduler *scheduler, struct vy_task *task)
 		return -1;
 	}
 
-	if (gc_lsn < 0) {
-		/*
-		 * If there is no last snapshot, i.e. we are in
-		 * the middle of join, we can delete compacted
-		 * run files right away.
-		 */
-		vy_log_tx_begin();
-		rlist_foreach_entry(run, &unused_runs, in_unused) {
-			if (vy_run_remove_files(index->env->path,
-						index->space_id, index->id,
-						run->id) == 0) {
-				vy_log_forget_run(run->id);
-			}
+	/*
+	 * Remove compacted run files that were created after
+	 * the last checkpoint (and hence are not referenced
+	 * by any checkpoint) immediately to save disk space.
+	 */
+	vy_log_tx_begin();
+	rlist_foreach_entry(run, &unused_runs, in_unused) {
+		if (run->dump_lsn > gc_lsn &&
+		    vy_run_remove_files(index->env->path,
+					index->space_id, index->id,
+					run->id) == 0) {
+			vy_log_forget_run(run->id);
 		}
-		vy_log_tx_try_commit();
 	}
+	vy_log_tx_try_commit();
 
 	/*
 	 * Account the new run if it is not empty,
diff --git a/test/vinyl/gc.result b/test/vinyl/gc.result
index f88b3996..b709135c 100644
--- a/test/vinyl/gc.result
+++ b/test/vinyl/gc.result
@@ -126,3 +126,81 @@ temp:drop()
 box.cfg{checkpoint_count = default_checkpoint_count}
 ---
 ...
+--
+-- Check that compacted run files that are not referenced
+-- by any checkpoint are deleted immediately (gh-3407).
+--
+test_run:cmd("create server test with script='vinyl/low_quota.lua'")
+---
+- true
+...
+test_run:cmd("start server test with args='1048576'")
+---
+- true
+...
+test_run:cmd('switch test')
+---
+- true
+...
+box.cfg{checkpoint_count = 2}
+---
+...
+fio = require('fio')
+---
+...
+fiber = require('fiber')
+---
+...
+s = box.schema.space.create('test', {engine = 'vinyl'})
+---
+...
+_ = s:create_index('pk', {run_count_per_level = 3})
+---
+...
+function count_runs() return #fio.glob(fio.pathjoin(box.cfg.vinyl_dir, s.id, s.index.pk.id, '*.run')) end
+---
+...
+_ = s:replace{1}
+---
+...
+box.snapshot()
+---
+- ok
+...
+_ = s:replace{2}
+---
+...
+box.snapshot()
+---
+- ok
+...
+count_runs() -- 2
+---
+- 2
+...
+for i = 1, 20 do s:replace{i, string.rep('x', 100 * 1024)} end
+---
+...
+while s.index.pk:info().disk.compact.count < 1 do fiber.sleep(0.001) end
+---
+...
+s.index.pk:info().disk.compact.count -- 1
+---
+- 1
+...
+count_runs() -- 3 (compacted runs created after checkpoint are deleted)
+---
+- 3
+...
+test_run:cmd('switch default')
+---
+- true
+...
+test_run:cmd("stop server test")
+---
+- true
+...
+test_run:cmd("cleanup server test")
+---
+- true
+...
diff --git a/test/vinyl/gc.test.lua b/test/vinyl/gc.test.lua
index 3974048b..32078f00 100644
--- a/test/vinyl/gc.test.lua
+++ b/test/vinyl/gc.test.lua
@@ -61,3 +61,38 @@ files = ls_vylog()
 temp:drop()
 
 box.cfg{checkpoint_count = default_checkpoint_count}
+
+--
+-- Check that compacted run files that are not referenced
+-- by any checkpoint are deleted immediately (gh-3407).
+--
+test_run:cmd("create server test with script='vinyl/low_quota.lua'")
+test_run:cmd("start server test with args='1048576'")
+test_run:cmd('switch test')
+
+box.cfg{checkpoint_count = 2}
+
+fio = require('fio')
+fiber = require('fiber')
+
+s = box.schema.space.create('test', {engine = 'vinyl'})
+_ = s:create_index('pk', {run_count_per_level = 3})
+
+function count_runs() return #fio.glob(fio.pathjoin(box.cfg.vinyl_dir, s.id, s.index.pk.id, '*.run')) end
+
+_ = s:replace{1}
+box.snapshot()
+_ = s:replace{2}
+box.snapshot()
+
+count_runs() -- 2
+
+for i = 1, 20 do s:replace{i, string.rep('x', 100 * 1024)} end
+while s.index.pk:info().disk.compact.count < 1 do fiber.sleep(0.001) end
+s.index.pk:info().disk.compact.count -- 1
+
+count_runs() -- 3 (compacted runs created after checkpoint are deleted)
+
+test_run:cmd('switch default')
+test_run:cmd("stop server test")
+test_run:cmd("cleanup server test")
-- 
2.11.0

Re: [PATCH] vinyl: remove runs not referenced by any checkpoint immediately

[Vladimir Davydov]

On Thu, May 17, 2018 at 07:09:52PM +0300, Vladimir Davydov wrote:
> If a compacted run was created after the last checkpoint, it is not
> needed to recover from any checkpoint and hence can be deleted right
> away to save disk space.
> 
> Closes #3407
> ---
> https://github.com/tarantool/tarantool/issues/3407
> https://github.com/tarantool/tarantool/commits/gh-3407-vy-remove-unreferenced-runs-immediately
> 
>  src/box/vy_scheduler.c | 27 +++++++++--------
>  test/vinyl/gc.result   | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  test/vinyl/gc.test.lua | 35 ++++++++++++++++++++++
>  3 files changed, 126 insertions(+), 14 deletions(-)
> 
> diff --git a/src/box/vy_scheduler.c b/src/box/vy_scheduler.c
> index e1853e5d..4c9103cf 100644
> --- a/src/box/vy_scheduler.c
> +++ b/src/box/vy_scheduler.c
> @@ -1139,22 +1139,21 @@ vy_task_compact_complete(struct vy_scheduler *scheduler, struct vy_task *task)
>  		return -1;
>  	}
>  
> -	if (gc_lsn < 0) {
> -		/*
> -		 * If there is no last snapshot, i.e. we are in
> -		 * the middle of join, we can delete compacted
> -		 * run files right away.
> -		 */
> -		vy_log_tx_begin();
> -		rlist_foreach_entry(run, &unused_runs, in_unused) {
> -			if (vy_run_remove_files(index->env->path,
> -						index->space_id, index->id,
> -						run->id) == 0) {
> -				vy_log_forget_run(run->id);
> -			}
> +	/*
> +	 * Remove compacted run files that were created after
> +	 * the last checkpoint (and hence are not referenced
> +	 * by any checkpoint) immediately to save disk space.
> +	 */
> +	vy_log_tx_begin();
> +	rlist_foreach_entry(run, &unused_runs, in_unused) {
> +		if (run->dump_lsn > gc_lsn &&
> +		    vy_run_remove_files(index->env->path,
> +					index->space_id, index->id,
> +					run->id) == 0) {
> +			vy_log_forget_run(run->id);
>  		}
> -		vy_log_tx_try_commit();
>  	}
> +	vy_log_tx_try_commit();
>  
>  	/*
>  	 * Account the new run if it is not empty,

Oops, this patch breaks vinyl/errinj_gc test, which doesn't expect
compaction to remove any files if ERRINJ_VY_GC is set. Fixed on the
branch. Here's the incremental diff:

diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index 55a68104..552d42ba 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -3389,10 +3389,6 @@ vy_gc_cb(const struct vy_log_record *record, void *cb_arg)
 		goto out;
 	}
 
-	ERROR_INJECT(ERRINJ_VY_GC,
-		     {say_error("error injection: vinyl run %lld not deleted",
-				(long long)record->run_id); goto out;});
-
 	/* Try to delete files. */
 	if (vy_run_remove_files(arg->env->path, arg->space_id,
 				arg->index_id, record->run_id) != 0)
diff --git a/src/box/vy_run.c b/src/box/vy_run.c
index edae5270..980bc4d2 100644
--- a/src/box/vy_run.c
+++ b/src/box/vy_run.c
@@ -2434,6 +2434,9 @@ int
 vy_run_remove_files(const char *dir, uint32_t space_id,
 		    uint32_t iid, int64_t run_id)
 {
+	ERROR_INJECT(ERRINJ_VY_GC,
+		     {say_error("error injection: vinyl run %lld not deleted",
+				(long long)run_id); return -1;});
 	int ret = 0;
 	char path[PATH_MAX];
 	for (int type = 0; type < vy_file_MAX; type++) {

Re: [PATCH] vinyl: remove runs not referenced by any checkpoint immediately

[Konstantin Osipov]

* Vladimir Davydov <vdavydov.dev@gmail.com> [18/05/17 19:13]:
> If a compacted run was created after the last checkpoint, it is not
> needed to recover from any checkpoint and hence can be deleted right
> away to save disk space.

Thank you for the patch.

This will hopefully solve the space amplification problem at
cloud.mail.ru. 

> 
> Closes #3407
> ---
> https://github.com/tarantool/tarantool/issues/3407
> https://github.com/tarantool/tarantool/commits/gh-3407-vy-remove-unreferenced-runs-immediately
> 
-- 
Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
http://tarantool.io - www.twitter.com/kostja_osipov

Re: [PATCH] vinyl: remove runs not referenced by any checkpoint immediately

[Konstantin Osipov]

* Konstantin Osipov <kostja@tarantool.org> [18/05/17 23:40]:
> * Vladimir Davydov <vdavydov.dev@gmail.com> [18/05/17 19:13]:
> > If a compacted run was created after the last checkpoint, it is not
> > needed to recover from any checkpoint and hence can be deleted right
> > away to save disk space.
> 
> Thank you for the patch.
> 
> This will hopefully solve the space amplification problem at
> cloud.mail.ru. 

I was not able to push my merge into 1.10. Apparently there are
more tests which rely on the error injection which you moved.

Please merge.

-- 
Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
http://tarantool.io - www.twitter.com/kostja_osipov