Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Andres Freund]

Hi,

Thank for all the work on this topic - I'd somehow accidentally marked this
thread as read when coming back from vacation...

Greetings,

Andres Freund

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Wed, Sep 1, 2021 at 5:33 PM Dilip Kumar  wrote:
>
> On Wed, Sep 1, 2021 at 5:23 PM Amit Kapila  wrote:
>>
>> On Wed, Sep 1, 2021 at 1:53 PM Dilip Kumar  wrote:
>> >
>>
>> The latest patch looks good to me. I have made some changes in the
>> comments, see attached. I am planning to push this tomorrow unless you
>> or others have any comments on it.
>
>
> These comments changes look good to me.
>

Pushed.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Wed, Sep 1, 2021 at 5:23 PM Amit Kapila  wrote:

> On Wed, Sep 1, 2021 at 1:53 PM Dilip Kumar  wrote:
> >
>
> The latest patch looks good to me. I have made some changes in the
> comments, see attached. I am planning to push this tomorrow unless you
> or others have any comments on it.
>

These comments changes look good to me.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Wed, Sep 1, 2021 at 1:53 PM Dilip Kumar  wrote:
>

The latest patch looks good to me. I have made some changes in the
comments, see attached. I am planning to push this tomorrow unless you
or others have any comments on it.

-- 
With Regards,
Amit Kapila.


v8-0001-Optimize-fileset-usage-in-apply-worker.patch
Description: Binary data

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Tue, Aug 31, 2021 at 3:20 PM Amit Kapila  wrote:
>
> On Fri, Aug 27, 2021 at 12:04 PM Dilip Kumar  wrote:
> >
>
> Few comments on v6-0002*
> =
> 1.
> -BufFileDeleteFileSet(FileSet *fileset, const char *name)
> +BufFileDeleteFileSet(FileSet *fileset, const char *name, bool missing_ok)
>  {
>   char segment_name[MAXPGPATH];
>   int segment = 0;
> @@ -358,7 +369,7 @@ BufFileDeleteFileSet(FileSet *fileset, const char *name)
>   for (;;)
>   {
>   FileSetSegmentName(segment_name, name, segment);
> - if (!FileSetDelete(fileset, segment_name, true))
> + if (!FileSetDelete(fileset, segment_name, !missing_ok))
>
> I don't think the usage of missing_ok is correct here. If you see
> FileSetDelete->PathNameDeleteTemporaryFile, it already tolerates that
> the file doesn't exist but gives an error only when it is unable to
> link. So, with this missing_ok users (say like worker.c) won't even
> get errors when they are not able to remove files whereas I think the
> need for the patch is to not get an error when the file doesn't exist.
> I think you don't need to change anything in the way we invoke
> FileSetDelete.

Right, fixed.

> 2.
> -static HTAB *xidhash = NULL;
> +static FileSet *stream_fileset = NULL;
>
> Can we keep this in LogicalRepWorker and initialize it accordingly?

Done

> 3.
> + /* Open the subxact file, if it does not exist, create it. */
> + fd = BufFileOpenFileSet(stream_fileset, path, O_RDWR, true);
> + if (fd == NULL)
> + fd = BufFileCreateFileSet(stream_fileset, path);
>
> I think retaining the existing comment: "Create the subxact file if it
> not already created, otherwise open the existing file." seems better
> here.

Done

> 4.
>   /*
> - * If there is no subtransaction then nothing to do, but if already have
> - * subxact file then delete that.
> + * If there are no subtransactions, there is nothing to be done, but if
> + * subxacts already exist, delete it.
>   */
>
> How about changing the above comment to something like: "Delete the
> subxacts file, if exists"?

Done

> 5. Can we slightly change the commit message as:
> Optimize fileset usage in apply worker.
>
> Use one fileset for the entire worker lifetime instead of using
> separate filesets for each streaming transaction. Now, the
> changes/subxacts files for every streaming transaction will be created
> under the same fileset and the files will be deleted after the
> transaction is completed.
>
> This patch extends the BufFileOpenFileSet and BufFileDeleteFileSet
> APIs to allow users to specify whether to give an error on missing
> files.

Done


-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From fade8ae2779e8aeda0d1fee3902a93eaedb0187f Mon Sep 17 00:00:00 2001
From: Dilip Kumar 
Date: Fri, 27 Aug 2021 11:49:12 +0530
Subject: [PATCH v7] Optimize fileset usage in apply worker

Use one fileset for the entire worker lifetime instead of using
separate filesets for each streaming transaction. Now, the
changes/subxacts files for every streaming transaction will be
created under the same fileset and the files will be deleted
after the transaction is completed.

This patch extends the BufFileOpenFileSet and BufFileDeleteFileSet
APIs to allow users to specify whether to give an error on missing
files.
---
 src/backend/replication/logical/launcher.c |   6 +-
 src/backend/replication/logical/worker.c   | 249 +
 src/backend/storage/file/buffile.c |  21 ++-
 src/backend/utils/sort/logtape.c   |   2 +-
 src/backend/utils/sort/sharedtuplestore.c  |   3 +-
 src/include/replication/worker_internal.h  |  11 +-
 src/include/storage/buffile.h  |   5 +-
 7 files changed, 80 insertions(+), 217 deletions(-)

diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 8b1772d..3fb4caa 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -379,6 +379,7 @@ retry:
 	worker->relid = relid;
 	worker->relstate = SUBREL_STATE_UNKNOWN;
 	worker->relstate_lsn = InvalidXLogRecPtr;
+	worker->stream_fileset = NULL;
 	worker->last_lsn = InvalidXLogRecPtr;
 	TIMESTAMP_NOBEGIN(worker->last_send_time);
 	TIMESTAMP_NOBEGIN(worker->last_recv_time);
@@ -648,8 +649,9 @@ logicalrep_worker_onexit(int code, Datum arg)
 
 	logicalrep_worker_detach();
 
-	/* Cleanup filesets used for streaming transactions. */
-	logicalrep_worker_cleanupfileset();
+	/* Cleanup fileset used for streaming transactions. */
+	if (MyLogicalRepWorker->stream_fileset != NULL)
+		FileSetDeleteAll(MyLogicalRepWorker->stream_fileset);
 
 	ApplyLauncherWakeup();
 }
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index bfb7d1a..a222cb3 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -236,20 +236,6 @@ static ApplyErrorCallbackArg apply_error_callback_arg =
 	.ts = 0,
 };
 
-/*
- * Stream xid hash entry. 

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Fri, Aug 27, 2021 at 12:04 PM Dilip Kumar  wrote:
>

Few comments on v6-0002*
=
1.
-BufFileDeleteFileSet(FileSet *fileset, const char *name)
+BufFileDeleteFileSet(FileSet *fileset, const char *name, bool missing_ok)
 {
  char segment_name[MAXPGPATH];
  int segment = 0;
@@ -358,7 +369,7 @@ BufFileDeleteFileSet(FileSet *fileset, const char *name)
  for (;;)
  {
  FileSetSegmentName(segment_name, name, segment);
- if (!FileSetDelete(fileset, segment_name, true))
+ if (!FileSetDelete(fileset, segment_name, !missing_ok))

I don't think the usage of missing_ok is correct here. If you see
FileSetDelete->PathNameDeleteTemporaryFile, it already tolerates that
the file doesn't exist but gives an error only when it is unable to
link. So, with this missing_ok users (say like worker.c) won't even
get errors when they are not able to remove files whereas I think the
need for the patch is to not get an error when the file doesn't exist.
I think you don't need to change anything in the way we invoke
FileSetDelete.

2.
-static HTAB *xidhash = NULL;
+static FileSet *stream_fileset = NULL;

Can we keep this in LogicalRepWorker and initialize it accordingly?

3.
+ /* Open the subxact file, if it does not exist, create it. */
+ fd = BufFileOpenFileSet(stream_fileset, path, O_RDWR, true);
+ if (fd == NULL)
+ fd = BufFileCreateFileSet(stream_fileset, path);

I think retaining the existing comment: "Create the subxact file if it
not already created, otherwise open the existing file." seems better
here.

4.
  /*
- * If there is no subtransaction then nothing to do, but if already have
- * subxact file then delete that.
+ * If there are no subtransactions, there is nothing to be done, but if
+ * subxacts already exist, delete it.
  */

How about changing the above comment to something like: "Delete the
subxacts file, if exists"?

5. Can we slightly change the commit message as:
Optimize fileset usage in apply worker.

Use one fileset for the entire worker lifetime instead of using
separate filesets for each streaming transaction. Now, the
changes/subxacts files for every streaming transaction will be created
under the same fileset and the files will be deleted after the
transaction is completed.

This patch extends the BufFileOpenFileSet and BufFileDeleteFileSet
APIs to allow users to specify whether to give an error on missing
files.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Tue, Aug 31, 2021 at 7:39 AM houzj.f...@fujitsu.com <
houzj.f...@fujitsu.com> wrote:

> From Mon, Aug 30, 2021 2:15 PM Masahiko Sawada 
> wrote:
> > On Fri, Aug 27, 2021 at 3:34 PM Dilip Kumar 
> wrote:
> > >
> > > On Fri, Aug 27, 2021 at 10:56 AM houzj.f...@fujitsu.com <
> houzj.f...@fujitsu.com> wrote:
> > > >
> > > > On Thu, Aug 26, 2021 2:18 PM Dilip Kumar 
> wrote:
> > > >
> > > > > The patch looks good to me, I have rebased 0002 atop this patch
> > > > > and also done some cosmetic fixes in 0002.
> >
> > Thank you for updating the patch!
> >
> > The patch looks good to me except for the below comment:
> >
> > +/* Delete the subxact file, if it exist. */
> > +subxact_filename(path, subid, xid);
> > +BufFileDeleteFileSet(stream_fileset, path, true);
> >
> > s/it exist/it exists/
>
> Except for Sawada-san's comment, the v6-0002 patch looks good to me.
>

Thanks, I will wait for a day to see if there are any other comments on
this, after that I will fix this one issue and post the updated patch.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

RE: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[houzj.f...@fujitsu.com]

From Mon, Aug 30, 2021 2:15 PM Masahiko Sawada  wrote:
> On Fri, Aug 27, 2021 at 3:34 PM Dilip Kumar  wrote:
> >
> > On Fri, Aug 27, 2021 at 10:56 AM houzj.f...@fujitsu.com 
> >  wrote:
> > >
> > > On Thu, Aug 26, 2021 2:18 PM Dilip Kumar  wrote:
> > >
> > > > The patch looks good to me, I have rebased 0002 atop this patch
> > > > and also done some cosmetic fixes in 0002.
> 
> Thank you for updating the patch!
> 
> The patch looks good to me except for the below comment:
> 
> +/* Delete the subxact file, if it exist. */
> +subxact_filename(path, subid, xid);
> +BufFileDeleteFileSet(stream_fileset, path, true);
> 
> s/it exist/it exists/

Except for Sawada-san's comment, the v6-0002 patch looks good to me.

Best regards,
Hou zj

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Mon, Aug 30, 2021 at 6:42 AM Masahiko Sawada  wrote:
>
> On Fri, Aug 27, 2021 at 2:25 PM Dilip Kumar  wrote:
> >
> > On Thu, Aug 26, 2021 at 2:10 PM Amit Kapila  wrote:
> >>
> >>
> >> Thanks, Sawada-San and Dilip for confirmation. I would like to commit
> >> this and the second patch (the second one still needs some more
> >> testing and review) for PG-15 as there is no bug per-se related to
> >> this work in PG-14 but I see an argument to commit this for PG-14 to
> >> keep the code (APIs) consistent. What do you think? Does anybody else
> >> have any opinion on this?
> >>
> >
> > IMHO, this is a fair amount of refactoring and this is actually an 
> > improvement patch so we should push it to v15.
>
> I think so too.
>

I have pushed the first patch in this series.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Masahiko Sawada]

On Fri, Aug 27, 2021 at 3:34 PM Dilip Kumar  wrote:
>
> On Fri, Aug 27, 2021 at 10:56 AM houzj.f...@fujitsu.com
>  wrote:
> >
> > On Thu, Aug 26, 2021 2:18 PM Dilip Kumar  wrote:
> >
> > > The patch looks good to me, I have rebased 0002 atop
> > > this patch and also done some cosmetic fixes in 0002.
> >
> > Here are some comments for the 0002 patch.
> >
> > 1)
> >
> > - * toplevel transaction. Each subscription has a separate set of files.
> > + * toplevel transaction. Each subscription has a separate files.
> >
> > a separate files => a separate file
>
> Done
>
> > 2)
> > +* Otherwise, just open it file for writing, in append mode.
> >  */
> >
> > open it file => open the file
>
> Done
>
> >
> > 3)
> > if (subxact_data.nsubxacts == 0)
> > {
> > -   if (ent->subxact_fileset)
> > -   {
> > -   cleanup_subxact_info();
> > -   FileSetDeleteAll(ent->subxact_fileset);
> > -   pfree(ent->subxact_fileset);
> > -   ent->subxact_fileset = NULL;
> > -   }
> > +   cleanup_subxact_info();
> > +   BufFileDeleteFileSet(stream_fileset, path, true);
> > +
> >
> > Before applying the patch, the code only invoke cleanup_subxact_info() when 
> > the
> > file exists. After applying the patch, it will invoke cleanup_subxact_info()
> > either the file exists or not. Is it correct ?
>
> I think this is just structure resetting at the end of the stream.
> Earlier the hash was telling us whether we have ever dirtied that
> structure or not but now we are not maintaining that hash so we just
> reset it at the end of the stream.  I don't think its any bad, in fact
> I think this is much cheaper compared to maining the hash.
>
> >
> > 4)
> > /*
> > -* If this is the first streamed segment, the file must not exist, 
> > so make
> > -* sure we're the ones creating it. Otherwise just open the file for
> > -* writing, in append mode.
> > +* If this is the first streamed segment, create the changes file.
> > +* Otherwise, just open it file for writing, in append mode.
> >  */
> > if (first_segment)
> > -   {
> > ...
> > -   if (found)
> > -   ereport(ERROR,
> > -   
> > (errcode(ERRCODE_PROTOCOL_VIOLATION),
> > -errmsg_internal("incorrect 
> > first-segment flag for streamed replication transaction")));
> > ...
> > -   }
> > +   stream_fd = BufFileCreateFileSet(stream_fileset, path);
> >
> >
> > Since the function BufFileCreateFileSet() doesn't check the file's 
> > existence,
> > the change here seems remove the file existence check which the old code 
> > did.
>
> Not really, we were just doing a sanity check of the in memory hash
> entry, now we don't maintain that so we don't need to do that.

Thank you for updating the patch!

The patch looks good to me except for the below comment:

+/* Delete the subxact file, if it exist. */
+subxact_filename(path, subid, xid);
+BufFileDeleteFileSet(stream_fileset, path, true);

s/it exist/it exists/

Regards,

-- 
Masahiko Sawada
EDB:  https://www.enterprisedb.com/

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Masahiko Sawada]

On Fri, Aug 27, 2021 at 2:25 PM Dilip Kumar  wrote:
>
> On Thu, Aug 26, 2021 at 2:10 PM Amit Kapila  wrote:
>>
>>
>> Thanks, Sawada-San and Dilip for confirmation. I would like to commit
>> this and the second patch (the second one still needs some more
>> testing and review) for PG-15 as there is no bug per-se related to
>> this work in PG-14 but I see an argument to commit this for PG-14 to
>> keep the code (APIs) consistent. What do you think? Does anybody else
>> have any opinion on this?
>>
>
> IMHO, this is a fair amount of refactoring and this is actually an 
> improvement patch so we should push it to v15.

I think so too.

Regards,

--
Masahiko Sawada
EDB:  https://www.enterprisedb.com/

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Fri, Aug 27, 2021 at 10:56 AM houzj.f...@fujitsu.com
 wrote:
>
> On Thu, Aug 26, 2021 2:18 PM Dilip Kumar  wrote:
>
> > The patch looks good to me, I have rebased 0002 atop
> > this patch and also done some cosmetic fixes in 0002.
>
> Here are some comments for the 0002 patch.
>
> 1)
>
> - * toplevel transaction. Each subscription has a separate set of files.
> + * toplevel transaction. Each subscription has a separate files.
>
> a separate files => a separate file

Done

> 2)
> +* Otherwise, just open it file for writing, in append mode.
>  */
>
> open it file => open the file

Done

>
> 3)
> if (subxact_data.nsubxacts == 0)
> {
> -   if (ent->subxact_fileset)
> -   {
> -   cleanup_subxact_info();
> -   FileSetDeleteAll(ent->subxact_fileset);
> -   pfree(ent->subxact_fileset);
> -   ent->subxact_fileset = NULL;
> -   }
> +   cleanup_subxact_info();
> +   BufFileDeleteFileSet(stream_fileset, path, true);
> +
>
> Before applying the patch, the code only invoke cleanup_subxact_info() when 
> the
> file exists. After applying the patch, it will invoke cleanup_subxact_info()
> either the file exists or not. Is it correct ?

I think this is just structure resetting at the end of the stream.
Earlier the hash was telling us whether we have ever dirtied that
structure or not but now we are not maintaining that hash so we just
reset it at the end of the stream.  I don't think its any bad, in fact
I think this is much cheaper compared to maining the hash.

>
> 4)
> /*
> -* If this is the first streamed segment, the file must not exist, so 
> make
> -* sure we're the ones creating it. Otherwise just open the file for
> -* writing, in append mode.
> +* If this is the first streamed segment, create the changes file.
> +* Otherwise, just open it file for writing, in append mode.
>  */
> if (first_segment)
> -   {
> ...
> -   if (found)
> -   ereport(ERROR,
> -   (errcode(ERRCODE_PROTOCOL_VIOLATION),
> -errmsg_internal("incorrect 
> first-segment flag for streamed replication transaction")));
> ...
> -   }
> +   stream_fd = BufFileCreateFileSet(stream_fileset, path);
>
>
> Since the function BufFileCreateFileSet() doesn't check the file's existence,
> the change here seems remove the file existence check which the old code did.

Not really, we were just doing a sanity check of the in memory hash
entry, now we don't maintain that so we don't need to do that.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From dfae7d9e3ae875c8db2de792e9a95ef86fef2b00 Mon Sep 17 00:00:00 2001
From: Amit Kapila 
Date: Wed, 25 Aug 2021 15:00:19 +0530
Subject: [PATCH v6 1/2] Refactor sharedfileset.c to separate out fileset
 implementation.

Move fileset related implementation out of sharedfileset.c to allow its
usage by backends that don't want to share filesets among different
processes. After this split, fileset infrastructure is used by both
sharedfileset.c and worker.c for the named temporary files that survive
across transactions.

Author: Dilip Kumar, based on suggestion by Andres Freund
Reviewed-by: Hou Zhijie, Masahiko Sawada, Amit Kapila
Discussion: https://postgr.es/m/e1mcc6u-0004ik...@gemulon.postgresql.org
---
 src/backend/replication/logical/launcher.c |   3 +
 src/backend/replication/logical/worker.c   |  82 ++
 src/backend/storage/file/Makefile  |   1 +
 src/backend/storage/file/buffile.c |  84 +-
 src/backend/storage/file/fd.c  |   2 +-
 src/backend/storage/file/fileset.c | 205 
 src/backend/storage/file/sharedfileset.c   | 244 +
 src/backend/utils/sort/logtape.c   |   8 +-
 src/backend/utils/sort/sharedtuplestore.c  |   5 +-
 src/include/replication/worker_internal.h  |   1 +
 src/include/storage/buffile.h  |  14 +-
 src/include/storage/fileset.h  |  40 +
 src/include/storage/sharedfileset.h|  14 +-
 src/tools/pgindent/typedefs.list   |   1 +
 14 files changed, 368 insertions(+), 336 deletions(-)
 create mode 100644 src/backend/storage/file/fileset.c
 create mode 100644 src/include/storage/fileset.h

diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index e3b11da..8b1772d 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -648,6 +648,9 @@ logicalrep_worker_onexit(int code, Datum arg)
 
 	logicalrep_worker_detach();
 
+	/* Cleanup filesets used for streaming transactions. */
+	logicalrep_worker_cleanupfileset();
+
 	ApplyLauncherWakeup();
 }
 
diff --git 

RE: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[houzj.f...@fujitsu.com]

On Fri, Aug 27, 2021 1:25 PM Dilip Kumar   wrote:
> On Thu, Aug 26, 2021 at 2:10 PM Amit Kapila  
> wrote:
> 
>> Thanks, Sawada-San and Dilip for confirmation. I would like to commit
>> this and the second patch (the second one still needs some more
>> testing and review) for PG-15 as there is no bug per-se related to
>> this work in PG-14 but I see an argument to commit this for PG-14 to
>> keep the code (APIs) consistent. What do you think? Does anybody else
>> have any opinion on this?

> IMHO, this is a fair amount of refactoring and this is actually an
> improvement patch so we should push it to v15.

+1

Best regards,
Hou zj

RE: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[houzj.f...@fujitsu.com]

On Thu, Aug 26, 2021 2:18 PM Dilip Kumar  wrote:

> The patch looks good to me, I have rebased 0002 atop
> this patch and also done some cosmetic fixes in 0002. 

Here are some comments for the 0002 patch.

1)

- * toplevel transaction. Each subscription has a separate set of files.
+ * toplevel transaction. Each subscription has a separate files.

a separate files => a separate file

2)
+* Otherwise, just open it file for writing, in append mode.
 */

open it file => open the file


3)
if (subxact_data.nsubxacts == 0)
{
-   if (ent->subxact_fileset)
-   {
-   cleanup_subxact_info();
-   FileSetDeleteAll(ent->subxact_fileset);
-   pfree(ent->subxact_fileset);
-   ent->subxact_fileset = NULL;
-   }
+   cleanup_subxact_info();
+   BufFileDeleteFileSet(stream_fileset, path, true);
+


Before applying the patch, the code only invoke cleanup_subxact_info() when the
file exists. After applying the patch, it will invoke cleanup_subxact_info()
either the file exists or not. Is it correct ?


4)
/*
-* If this is the first streamed segment, the file must not exist, so 
make
-* sure we're the ones creating it. Otherwise just open the file for
-* writing, in append mode.
+* If this is the first streamed segment, create the changes file.
+* Otherwise, just open it file for writing, in append mode.
 */
if (first_segment)
-   {
...
-   if (found)
-   ereport(ERROR,
-   (errcode(ERRCODE_PROTOCOL_VIOLATION),
-errmsg_internal("incorrect 
first-segment flag for streamed replication transaction")));
...
-   }
+   stream_fd = BufFileCreateFileSet(stream_fileset, path);


Since the function BufFileCreateFileSet() doesn't check the file's existence,
the change here seems remove the file existence check which the old code did.


Best regards,
Hou zj

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Thu, Aug 26, 2021 at 2:10 PM Amit Kapila  wrote:

>
> Thanks, Sawada-San and Dilip for confirmation. I would like to commit
> this and the second patch (the second one still needs some more
> testing and review) for PG-15 as there is no bug per-se related to
> this work in PG-14 but I see an argument to commit this for PG-14 to
> keep the code (APIs) consistent. What do you think? Does anybody else
> have any opinion on this?
>
>
IMHO, this is a fair amount of refactoring and this is actually an
improvement patch so we should push it to v15.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Thu, Aug 26, 2021 at 11:47 AM Dilip Kumar  wrote:
>
> On Wed, Aug 25, 2021 at 5:49 PM Amit Kapila  wrote:
>>
>> On Tue, Aug 24, 2021 at 3:55 PM Dilip Kumar  wrote:
>> >
>> > On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila  
>> > wrote:
>> >
>>
>> The first patch looks good to me. I have made minor changes to the
>> attached patch. The changes include: fixing compilation warning, made
>> some comment changes, ran pgindent, and few other cosmetic changes. If
>> you are fine with the attached, then kindly rebase the second patch
>> atop it.
>>
>
> The patch looks good to me,
>

Thanks, Sawada-San and Dilip for confirmation. I would like to commit
this and the second patch (the second one still needs some more
testing and review) for PG-15 as there is no bug per-se related to
this work in PG-14 but I see an argument to commit this for PG-14 to
keep the code (APIs) consistent. What do you think? Does anybody else
have any opinion on this?

Below is a summary of each of the patches for those who are not
following this closely:
Patch-1: The purpose of this patch is to refactor sharedfileset.c to
separate out fileset implementation. Basically, this moves the fileset
related implementation out of sharedfileset.c to allow its usage by
backends that don't want to share filesets among different processes.
After this split, fileset infrastructure is used by both
sharedfileset.c and worker.c for the named temporary files that
survive across transactions. This is suggested by Andres to have a
cleaner API and its usage.

Patch-2: Allow to use single fileset in worker.c (for the lifetime of
worker) instead of using a separate fileset for each remote
transaction. After this, the files to record changes for each remote
transaction will be created under the same fileset and the files will
be deleted after the transaction is completed. This is suggested by
Thomas to allow better resource usage.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Wed, Aug 25, 2021 at 5:49 PM Amit Kapila  wrote:

> On Tue, Aug 24, 2021 at 3:55 PM Dilip Kumar  wrote:
> >
> > On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila 
> wrote:
> >
>
> The first patch looks good to me. I have made minor changes to the
> attached patch. The changes include: fixing compilation warning, made
> some comment changes, ran pgindent, and few other cosmetic changes. If
> you are fine with the attached, then kindly rebase the second patch
> atop it.
>
>
The patch looks good to me, I have rebased 0002 atop this patch and also
done some cosmetic fixes in 0002.


-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From 3558cdc8a4f77e3c9092bbaeded451eaaa1feca4 Mon Sep 17 00:00:00 2001
From: Amit Kapila 
Date: Wed, 25 Aug 2021 15:00:19 +0530
Subject: [PATCH v5 1/2] Refactor sharedfileset.c to separate out fileset
 implementation.

Move fileset related implementation out of sharedfileset.c to allow its
usage by backends that don't want to share filesets among different
processes. After this split, fileset infrastructure is used by both
sharedfileset.c and worker.c for the named temporary files that survive
across transactions.

Author: Dilip Kumar, based on suggestion by Andres Freund
Reviewed-by: Hou Zhijie, Masahiko Sawada, Amit Kapila
Discussion: https://postgr.es/m/e1mcc6u-0004ik...@gemulon.postgresql.org
---
 src/backend/replication/logical/launcher.c |   3 +
 src/backend/replication/logical/worker.c   |  82 ++
 src/backend/storage/file/Makefile  |   1 +
 src/backend/storage/file/buffile.c |  84 +-
 src/backend/storage/file/fd.c  |   2 +-
 src/backend/storage/file/fileset.c | 205 
 src/backend/storage/file/sharedfileset.c   | 244 +
 src/backend/utils/sort/logtape.c   |   8 +-
 src/backend/utils/sort/sharedtuplestore.c  |   5 +-
 src/include/replication/worker_internal.h  |   1 +
 src/include/storage/buffile.h  |  14 +-
 src/include/storage/fileset.h  |  40 +
 src/include/storage/sharedfileset.h|  14 +-
 src/tools/pgindent/typedefs.list   |   1 +
 14 files changed, 368 insertions(+), 336 deletions(-)
 create mode 100644 src/backend/storage/file/fileset.c
 create mode 100644 src/include/storage/fileset.h

diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index e3b11da..8b1772d 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -648,6 +648,9 @@ logicalrep_worker_onexit(int code, Datum arg)
 
 	logicalrep_worker_detach();
 
+	/* Cleanup filesets used for streaming transactions. */
+	logicalrep_worker_cleanupfileset();
+
 	ApplyLauncherWakeup();
 }
 
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 38b493e..6adc6ddd 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -39,13 +39,13 @@
  * BufFile infrastructure supports temporary files that exceed the OS file size
  * limit, (b) provides a way for automatic clean up on the error and (c) provides
  * a way to survive these files across local transactions and allow to open and
- * close at stream start and close. We decided to use SharedFileSet
+ * close at stream start and close. We decided to use FileSet
  * infrastructure as without that it deletes the files on the closure of the
  * file and if we decide to keep stream files open across the start/stop stream
  * then it will consume a lot of memory (more than 8K for each BufFile and
  * there could be multiple such BufFiles as the subscriber could receive
  * multiple start/stop streams for different transactions before getting the
- * commit). Moreover, if we don't use SharedFileSet then we also need to invent
+ * commit). Moreover, if we don't use FileSet then we also need to invent
  * a new way to pass filenames to BufFile APIs so that we are allowed to open
  * the file we desired across multiple stream-open calls for the same
  * transaction.
@@ -231,8 +231,8 @@ typedef struct ApplyExecutionData
 typedef struct StreamXidHash
 {
 	TransactionId xid;			/* xid is the hash key and must be first */
-	SharedFileSet *stream_fileset;	/* shared file set for stream data */
-	SharedFileSet *subxact_fileset; /* shared file set for subxact info */
+	FileSet*stream_fileset; /* file set for stream data */
+	FileSet*subxact_fileset;	/* file set for subxact info */
 } StreamXidHash;
 
 static MemoryContext ApplyMessageContext = NULL;
@@ -255,8 +255,8 @@ static bool in_streamed_transaction = false;
 static TransactionId stream_xid = InvalidTransactionId;
 
 /*
- * Hash table for storing the streaming xid information along with shared file
- * set for streaming and subxact files.
+ * Hash table for storing the streaming xid information along with filesets
+ * for streaming and subxact files.
  */
 static HTAB *xidhash = 

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Masahiko Sawada]

On Wed, Aug 25, 2021 at 9:19 PM Amit Kapila  wrote:
>
> On Tue, Aug 24, 2021 at 3:55 PM Dilip Kumar  wrote:
> >
> > On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila  
> > wrote:
> >
>
> The first patch looks good to me. I have made minor changes to the
> attached patch. The changes include: fixing compilation warning, made
> some comment changes, ran pgindent, and few other cosmetic changes. If
> you are fine with the attached, then kindly rebase the second patch
> atop it.

The patch looks good to me.

Regards,

-- 
Masahiko Sawada
EDB:  https://www.enterprisedb.com/

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Tue, Aug 24, 2021 at 3:55 PM Dilip Kumar  wrote:
>
> On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila  wrote:
>

The first patch looks good to me. I have made minor changes to the
attached patch. The changes include: fixing compilation warning, made
some comment changes, ran pgindent, and few other cosmetic changes. If
you are fine with the attached, then kindly rebase the second patch
atop it.

-- 
With Regards,
Amit Kapila.


v5-0001-Refactor-sharedfileset.c-to-separate-out-fileset-.patch
Description: Binary data

RE: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[houzj.f...@fujitsu.com]

On Tuesday, August 24, 2021 6:25 PM Dilip Kumar  wrote:
> On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila  wrote:
> 
> > > I was also thinking about the same, does it make sense to name it
> > > just ""%s/%s%lu.%u.fileset"?
> 
> Done
> 
> > I think it is reasonable to use .fileset as proposed by you.
> >
> > Few other comments:
> Done

After applying the patch, I tested the impacted features
(parallel hashjoin/btree build) with different settings
(log_temp_files/maintenance_work_mem/parallel_leader_participation/workers)
, and the patch works well.

One thing I noticed is that when enable log_temp_files, the pathname in log
changed from "xxx.sharedfileset" to "xxx.fileset", and I also noticed some
blogs[1] reference the old path name. Although, I think it doesn't matter, just
share the information here in case someone has different opinions.


Some minor thing I noticed in the patch:

1)
it seems we can add "FileSet" to typedefs.list

2)
The commit message in 0002 used "shared fileset" which should be "fileset",
---
Instead of using a separate shared fileset for each xid, use one shared
fileset for whole lifetime of the worker...
---

[1] https://blog.dbi-services.com/about-temp_tablespaces-in-postgresql/

Best regards,
Hou zj

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Tue, Aug 24, 2021 at 12:26 PM Amit Kapila  wrote:

> > I was also thinking about the same, does it make sense to name it just
> > ""%s/%s%lu.%u.fileset"?

Done

> I think it is reasonable to use .fileset as proposed by you.
>
> Few other comments:
> =
> 1.
> + /*
> + * Register before-shmem-exit hook to ensure filesets are dropped while we
> + * can still report stats for underlying temporary files.
> + */
> + before_shmem_exit(worker_cleanup, (Datum) 0);
> +
>
> Do we really need to register a new callback here? Won't the existing
> logical replication worker exit routine (logicalrep_worker_onexit) be
> sufficient for this patch's purpose?

Right, we don't need an extra function for this.

> 2.
> - SharedFileSet *fileset; /* space for segment files if shared */
> - const char *name; /* name of this BufFile if shared */
> + FileSet*fileset; /* space for fileset for fileset based file */
> + const char *name; /* name of this BufFile */
>
> The comments for the above two variables can be written as (a) space
> for fileset based segment files, (b) name of fileset based BufFile.

Done

> 3.
>  /*
> - * Create a new segment file backing a shared BufFile.
> + * Create a new segment file backing a fileset BufFile.
>   */
>  static File
> -MakeNewSharedSegment(BufFile *buffile, int segment)
> +MakeNewSegment(BufFile *buffile, int segment)
>
> I think it is better to name this function as MakeNewFileSetSegment.
> You can slightly change the comment as: "Create a new segment file
> backing a fileset based BufFile."

 Make sense

> 4.
> /*
>   * It is possible that there are files left over from before a crash
> - * restart with the same name.  In order for BufFileOpenShared() not to
> + * restart with the same name.  In order for BufFileOpen() not to
>   * get confused about how many segments there are, we'll unlink the next
>
> Typo. /BufFileOpen/BufFileOpenFileSet

Fixed

> 5.
>  static void
> -SharedSegmentName(char *name, const char *buffile_name, int segment)
> +SegmentName(char *name, const char *buffile_name, int segment)
>
> Can we name this as FileSetSegmentName?

Done

> 6.
>   *
> - * The naming scheme for shared BufFiles is left up to the calling code.  The
> + * The naming scheme for fileset BufFiles is left up to the calling code.
>
> Isn't it better to say "... fileset based BufFiles .."?

Done

> 7.
> + * FileSets provide a temporary namespace (think directory) so that files can
> + * be discovered by name
>
> A full stop is missing at the end of the statement.

Fixed

> 8.
> + *
> + * The callers are expected to explicitly remove such files by using
> + * SharedFileSetDelete/ SharedFileSetDeleteAll.
> + *
> + * Files will be distributed over the tablespaces configured in
> + * temp_tablespaces.
> + *
> + * Under the covers the set is one or more directories which will eventually
> + * be deleted.
> + */
> +void
> +FileSetInit(FileSet *fileset)
>
> Is there a need to mention 'Shared' in API names (SharedFileSetDelete/
> SharedFileSetDeleteAll) in the comments? Also, there doesn't seem to
> be a need for extra space before *DeleteAll API in comments.

Fixed

> 9.
>  * Files will be distributed over the tablespaces configured in
>  * temp_tablespaces.
>  *
>  * Under the covers the set is one or more directories which will eventually
>  * be deleted.
>  */
> void
> SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)
>
> I think we can remove the part of the above comment where it says
> "Files will be distributed over ..." as that is already mentioned atop
> FileSetInit.

Done

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From 94a8a22726f08f07259b49ccee340ab1d4cba116 Mon Sep 17 00:00:00 2001
From: Dilip Kumar 
Date: Wed, 18 Aug 2021 15:52:21 +0530
Subject: [PATCH v3 1/2] Sharedfileset refactoring

Currently, sharedfileset.c is designed for a very specific purpose i.e.
one backend could create the fileset and that could be shared across
multiple backends so the fileset should be created in DSM.  But in some
use cases, we need exact behavior as sharedfileset that the files are
created under this should be named files and should also survive the
transaction and should be allowed to be opened and closed.  In this
patch  we have refactored these files such that there will be two
files a) fileset.c which will provide general-purpose interfaces
b) sharedfileset.c, which will internally used fileset.c but this
will be specific for DSM-based filesets.
---
 src/backend/replication/logical/launcher.c |   3 +
 src/backend/replication/logical/worker.c   |  83 ++
 src/backend/storage/file/Makefile  |   1 +
 src/backend/storage/file/buffile.c |  84 +-
 src/backend/storage/file/fd.c  |   2 +-
 src/backend/storage/file/fileset.c | 204 
 src/backend/storage/file/sharedfileset.c   | 244 +
 src/backend/utils/sort/logtape.c   |   8 +-
 

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Mon, Aug 23, 2021 at 3:13 PM Dilip Kumar  wrote:
>
> On Mon, Aug 23, 2021 at 1:43 PM Amit Kapila  wrote:
>
> Note: merge comments from multiple mails
>
> > > I think we should handle that in worker.c itself, by adding a
> > > before_dsm_detach function before_shmem_exit right?
> > >
> >
> > Yeah, I thought of handling it in worker.c similar to what you've in 0002 
> > patch.
> >
>
> I have done handling in worker.c
>
> On Mon, Aug 23, 2021 at 9:11 AM houzj.f...@fujitsu.com
>  wrote:
> >
> > On Sat, Aug 21, 2021 8:38 PM Dilip Kumar  wrote:
> >
> > 1)
> > +   TempTablespacePath(tempdirpath, tablespace);
> > +   snprintf(path, MAXPGPATH, "%s/%s%lu.%u.sharedfileset",
> > +tempdirpath, PG_TEMP_FILE_PREFIX,
> > +(unsigned long) fileset->creator_pid, 
> > fileset->number);
> >
> > do we need to use different filename for shared and un-shared fileset ?
>
> I was also thinking about the same, does it make sense to name it just
> ""%s/%s%lu.%u.fileset"?
>

I think it is reasonable to use .fileset as proposed by you.

Few other comments:
=
1.
+ /*
+ * Register before-shmem-exit hook to ensure filesets are dropped while we
+ * can still report stats for underlying temporary files.
+ */
+ before_shmem_exit(worker_cleanup, (Datum) 0);
+

Do we really need to register a new callback here? Won't the existing
logical replication worker exit routine (logicalrep_worker_onexit) be
sufficient for this patch's purpose?

2.
- SharedFileSet *fileset; /* space for segment files if shared */
- const char *name; /* name of this BufFile if shared */
+ FileSet*fileset; /* space for fileset for fileset based file */
+ const char *name; /* name of this BufFile */

The comments for the above two variables can be written as (a) space
for fileset based segment files, (b) name of fileset based BufFile.

3.
 /*
- * Create a new segment file backing a shared BufFile.
+ * Create a new segment file backing a fileset BufFile.
  */
 static File
-MakeNewSharedSegment(BufFile *buffile, int segment)
+MakeNewSegment(BufFile *buffile, int segment)

I think it is better to name this function as MakeNewFileSetSegment.
You can slightly change the comment as: "Create a new segment file
backing a fileset based BufFile."

4.
/*
  * It is possible that there are files left over from before a crash
- * restart with the same name.  In order for BufFileOpenShared() not to
+ * restart with the same name.  In order for BufFileOpen() not to
  * get confused about how many segments there are, we'll unlink the next

Typo. /BufFileOpen/BufFileOpenFileSet

5.
 static void
-SharedSegmentName(char *name, const char *buffile_name, int segment)
+SegmentName(char *name, const char *buffile_name, int segment)

Can we name this as FileSetSegmentName?

6.
  *
- * The naming scheme for shared BufFiles is left up to the calling code.  The
+ * The naming scheme for fileset BufFiles is left up to the calling code.

Isn't it better to say "... fileset based BufFiles .."?

7.
+ * FileSets provide a temporary namespace (think directory) so that files can
+ * be discovered by name

A full stop is missing at the end of the statement.

8.
+ *
+ * The callers are expected to explicitly remove such files by using
+ * SharedFileSetDelete/ SharedFileSetDeleteAll.
+ *
+ * Files will be distributed over the tablespaces configured in
+ * temp_tablespaces.
+ *
+ * Under the covers the set is one or more directories which will eventually
+ * be deleted.
+ */
+void
+FileSetInit(FileSet *fileset)

Is there a need to mention 'Shared' in API names (SharedFileSetDelete/
SharedFileSetDeleteAll) in the comments? Also, there doesn't seem to
be a need for extra space before *DeleteAll API in comments.

9.
 * Files will be distributed over the tablespaces configured in
 * temp_tablespaces.
 *
 * Under the covers the set is one or more directories which will eventually
 * be deleted.
 */
void
SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg)

I think we can remove the part of the above comment where it says
"Files will be distributed over ..." as that is already mentioned atop
FileSetInit.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Mon, Aug 23, 2021 at 1:43 PM Amit Kapila  wrote:

Note: merge comments from multiple mails

> > I think we should handle that in worker.c itself, by adding a
> > before_dsm_detach function before_shmem_exit right?
> >
>
> Yeah, I thought of handling it in worker.c similar to what you've in 0002 
> patch.
>

I have done handling in worker.c

On Mon, Aug 23, 2021 at 9:11 AM houzj.f...@fujitsu.com
 wrote:
>
> On Sat, Aug 21, 2021 8:38 PM Dilip Kumar  wrote:
>
> 1)
> +   TempTablespacePath(tempdirpath, tablespace);
> +   snprintf(path, MAXPGPATH, "%s/%s%lu.%u.sharedfileset",
> +tempdirpath, PG_TEMP_FILE_PREFIX,
> +(unsigned long) fileset->creator_pid, 
> fileset->number);
>
> do we need to use different filename for shared and un-shared fileset ?

I was also thinking about the same, does it make sense to name it just
""%s/%s%lu.%u.fileset"?

On Mon, Aug 23, 2021 at 1:08 PM Masahiko Sawada  wrote:

> Here are some comments on 0001 patch:
>
> +/*
> + * Initialize a space for temporary files. This API can be used by shared
> + * fileset as well as if the temporary files are used only by single backend
> + * but the files need to be opened and closed multiple times and also the
> + * underlying files need to survive across transactions.
> + *
> + * Files will be distributed over the tablespaces configured in
> + * temp_tablespaces.
> + *
> + * Under the covers the set is one or more directories which will eventually
> + * be deleted.
> + */
>
> I think it's better to mention cleaning up here like we do in the
> comment of SharedFileSetInit().

Right, done

>
> ---
> I think we need to clean up both stream_fileset and subxact_fileset on
> proc exit. In 0002 patch cleans up the fileset but I think we need to
> do that also in 0001 patch.

Done

> ---
> There still are some comments using "shared fileset" in both buffile.c
> and worker.c.

Done


-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com
From ced3a5e0222c2f89a977add167615f09d99d107a Mon Sep 17 00:00:00 2001
From: Dilip Kumar 
Date: Wed, 18 Aug 2021 15:52:21 +0530
Subject: [PATCH v2 1/2] Sharedfileset refactoring

Currently, sharedfileset.c is designed for a very specific purpose i.e.
one backend could create the fileset and  could be shared across multiple
backend so the fileset should be created in DSM.  But in some use cases,
we need exact behavior as sharedfileset that the files created under this
should be named files and should survive the transaction and should allow
to have feature of open and close.  In this patch  we have refactored
these files such that there will be two files a) fileset.c which will provide
general-purpose interfaces b) sharedfileset.c, which will internally used
fileset.c but this will be specific for DSM-based filesets.
---
 src/backend/replication/logical/worker.c  |  89 +++
 src/backend/storage/file/Makefile |   1 +
 src/backend/storage/file/buffile.c|  82 +-
 src/backend/storage/file/fd.c |   2 +-
 src/backend/storage/file/fileset.c| 204 +
 src/backend/storage/file/sharedfileset.c  | 239 +-
 src/backend/utils/sort/logtape.c  |   8 +-
 src/backend/utils/sort/sharedtuplestore.c |   5 +-
 src/include/storage/buffile.h |  12 +-
 src/include/storage/fileset.h |  40 +
 src/include/storage/sharedfileset.h   |  14 +-
 11 files changed, 366 insertions(+), 330 deletions(-)
 create mode 100644 src/backend/storage/file/fileset.c
 create mode 100644 src/include/storage/fileset.h

diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index ecaed15..d98ebab 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -39,13 +39,13 @@
  * BufFile infrastructure supports temporary files that exceed the OS file size
  * limit, (b) provides a way for automatic clean up on the error and (c) provides
  * a way to survive these files across local transactions and allow to open and
- * close at stream start and close. We decided to use SharedFileSet
+ * close at stream start and close. We decided to use FileSet
  * infrastructure as without that it deletes the files on the closure of the
  * file and if we decide to keep stream files open across the start/stop stream
  * then it will consume a lot of memory (more than 8K for each BufFile and
  * there could be multiple such BufFiles as the subscriber could receive
  * multiple start/stop streams for different transactions before getting the
- * commit). Moreover, if we don't use SharedFileSet then we also need to invent
+ * commit). Moreover, if we don't use FileSet then we also need to invent
  * a new way to pass filenames to BufFile APIs so that we are allowed to open
  * the file we desired across multiple stream-open calls for the same
  * transaction.
@@ -231,8 +231,8 @@ typedef struct 

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Mon, Aug 23, 2021 at 12:52 PM Dilip Kumar  wrote:
>
> On Mon, Aug 23, 2021 at 11:43 AM Amit Kapila  wrote:
> >
> > On Mon, Aug 23, 2021 at 9:53 AM Dilip Kumar  wrote:
> > >
> > > On Mon, Aug 23, 2021 at 9:11 AM houzj.f...@fujitsu.com
> > >  wrote:
> > >
> > > > 4)
> > > > -extern File SharedFileSetCreate(SharedFileSet *fileset, const char 
> > > > *name);
> > > > -extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name,
> > > > - int mode);
> > > > -extern bool SharedFileSetDelete(SharedFileSet *fileset, const char 
> > > > *name,
> > > > -   bool 
> > > > error_on_failure);
> > > >  extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
> > > > -extern void SharedFileSetUnregister(SharedFileSet *input_fileset);
> > > >
> > > > I noticed the patch delete part of public api, is it better to keep the 
> > > > old api and
> > > > let them invoke new api internally ? Having said that, I didn’t find 
> > > > any open source
> > > > extension use these old api, so it might be fine to delete them.
> > >
> > > Right, those were internally used by buffile.c but now we have changed
> > > buffile.c to directly use the fileset interfaces, so we better remove
> > > them.
> > >
> >
> > I also don't see any reason to keep those exposed from
> > sharedfileset.h. I see that even in the original commit dc6c4c9dc2,
> > these APIs seem to be introduced to be used by buffile. Andres/Thomas,
> > do let us know if you think otherwise?
> >
> > One more comment:
> > I think v1-0001-Sharedfileset-refactoring doesn't have a way for
> > cleaning up worker.c temporary files on error/exit. It is better to
> > have that to make it an independent patch.
>
> I think we should handle that in worker.c itself, by adding a
> before_dsm_detach function before_shmem_exit right?
>

Yeah, I thought of handling it in worker.c similar to what you've in 0002 patch.

-- 
With Regards,
Amit Kapila.

Re: Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Dilip Kumar]

On Mon, Aug 23, 2021 at 11:43 AM Amit Kapila  wrote:
>
> On Mon, Aug 23, 2021 at 9:53 AM Dilip Kumar  wrote:
> >
> > On Mon, Aug 23, 2021 at 9:11 AM houzj.f...@fujitsu.com
> >  wrote:
> >
> > > 4)
> > > -extern File SharedFileSetCreate(SharedFileSet *fileset, const char 
> > > *name);
> > > -extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name,
> > > - int mode);
> > > -extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
> > > -   bool 
> > > error_on_failure);
> > >  extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
> > > -extern void SharedFileSetUnregister(SharedFileSet *input_fileset);
> > >
> > > I noticed the patch delete part of public api, is it better to keep the 
> > > old api and
> > > let them invoke new api internally ? Having said that, I didn’t find any 
> > > open source
> > > extension use these old api, so it might be fine to delete them.
> >
> > Right, those were internally used by buffile.c but now we have changed
> > buffile.c to directly use the fileset interfaces, so we better remove
> > them.
> >
>
> I also don't see any reason to keep those exposed from
> sharedfileset.h. I see that even in the original commit dc6c4c9dc2,
> these APIs seem to be introduced to be used by buffile. Andres/Thomas,
> do let us know if you think otherwise?
>
> One more comment:
> I think v1-0001-Sharedfileset-refactoring doesn't have a way for
> cleaning up worker.c temporary files on error/exit. It is better to
> have that to make it an independent patch.

I think we should handle that in worker.c itself, by adding a
before_dsm_detach function before_shmem_exit right?  Or you are
thinking that in FileSetInit, we keep the mechanism of filesetlist
like we were doing in SharedFileSetInit?  I think that will just add
unnecessary complexity in the first patch which will eventually go
away in the second patch.  And if we do that then SharedFileSetInit
can not directly use the FileSetInit, otherwise, the dsm based fileset
will also get registered for cleanup in filesetlist so for that we
might need to pass one parameter to the FileSetInit() that whether to
register for cleanup or not and that will again not look clean because
now we are again adding the conditional cleanup, IMHO that is the same
problem what we are trying to cleanup in SharedFileSetInit by
introducing a new FileSetInit.

I think what we can do is, introduce a new function
FileSetInitInternal(), that will do what FileSetInit() is doing today
and now both SharedFileSetInit() and the FileSetInit() will call this
function, and along with that SharedFileSetInit(), will register the
dsm based cleanup and FileSetInit() will do the filesetlist based
cleanup.  But IMHO, we should try to go in this direction only if we
are sure that we want to commit the first patch and not the second.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Separate out FileSet from SharedFileSet (was Re: pgsql: pgstat: Bring up pgstat in BaseInit() to fix uninitialized use o)

[Amit Kapila]

On Mon, Aug 23, 2021 at 9:53 AM Dilip Kumar  wrote:
>
> On Mon, Aug 23, 2021 at 9:11 AM houzj.f...@fujitsu.com
>  wrote:
>
> > 4)
> > -extern File SharedFileSetCreate(SharedFileSet *fileset, const char *name);
> > -extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name,
> > - int mode);
> > -extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
> > -   bool 
> > error_on_failure);
> >  extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
> > -extern void SharedFileSetUnregister(SharedFileSet *input_fileset);
> >
> > I noticed the patch delete part of public api, is it better to keep the old 
> > api and
> > let them invoke new api internally ? Having said that, I didn’t find any 
> > open source
> > extension use these old api, so it might be fine to delete them.
>
> Right, those were internally used by buffile.c but now we have changed
> buffile.c to directly use the fileset interfaces, so we better remove
> them.
>

I also don't see any reason to keep those exposed from
sharedfileset.h. I see that even in the original commit dc6c4c9dc2,
these APIs seem to be introduced to be used by buffile. Andres/Thomas,
do let us know if you think otherwise?

One more comment:
I think v1-0001-Sharedfileset-refactoring doesn't have a way for
cleaning up worker.c temporary files on error/exit. It is better to
have that to make it an independent patch.

-- 
With Regards,
Amit Kapila.