aboutsummaryrefslogtreecommitdiff
path: root/src/backend/replication/logical/logical.c
Commit message (Collapse)AuthorAge
* Fix a possibility of logical replication slot's restart_lsn going backwards.Masahiko Sawada2024-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously LogicalIncreaseRestartDecodingForSlot() accidentally accepted any LSN as the candidate_lsn and candidate_valid after the restart_lsn of the replication slot was updated, so it potentially caused the restart_lsn to move backwards. A scenario where this could happen in logical replication is: after a logical replication restart, based on previous candidate_lsn and candidate_valid values in memory, the restart_lsn advances upon receiving a subscriber acknowledgment. Then, logical decoding restarts from an older point, setting candidate_lsn and candidate_valid based on an old RUNNING_XACTS record. Subsequent subscriber acknowledgments then update the restart_lsn to an LSN older than the current value. In the reported case, after WAL files were removed by a checkpoint, the retreated restart_lsn prevented logical replication from restarting due to missing WAL segments. This change essentially modifies the 'if' condition to 'else if' condition within the function. The previous code had an asymmetry in this regard compared to LogicalIncreaseXminForSlot(), which does almost the same thing for different fields. The WAL removal issue was reported by Hubert Depesz Lubaczewski. Backpatch to all supported versions, since the bug exists since 9.4 where logical decoding was introduced. Reviewed-by: Tomas Vondra, Ashutosh Bapat, Amit Kapila Discussion: https://postgr.es/m/Yz2hivgyjS1RfMKs%40depesz.com Discussion: https://postgr.es/m/85fff40e-148b-4e86-b921-b4b846289132%40vondra.me Backpatch-through: 13
* Fix possibility of logical decoding partial transaction changes.Masahiko Sawada2024-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When creating and initializing a logical slot, the restart_lsn is set to the latest WAL insertion point (or the latest replay point on standbys). Subsequently, WAL records are decoded from that point to find the start point for extracting changes in the DecodingContextFindStartpoint() function. Since the initial restart_lsn could be in the middle of a transaction, the start point must be a consistent point where we won't see the data for partial transactions. Previously, when not building a full snapshot, serialized snapshots were restored, and the SnapBuild jumps to the consistent state even while finding the start point. Consequently, the slot's restart_lsn and confirmed_flush could be set to the middle of a transaction. This could lead to various unexpected consequences. Specifically, there were reports of logical decoding decoding partial transactions, and assertion failures occurred because only subtransactions were decoded without decoding their top-level transaction until decoding the commit record. To resolve this issue, the changes prevent restoring the serialized snapshot and jumping to the consistent state while finding the start point. On v17 and HEAD, a flag indicating whether snapshot restores should be skipped has been added to the SnapBuild struct, and SNAPBUILD_VERSION has been bumpded. On backbranches, the flag is stored in the LogicalDecodingContext instead, preserving on-disk compatibility. Backpatch to all supported versions. Reported-by: Drew Callahan Reviewed-by: Amit Kapila, Hayato Kuroda Discussion: https://postgr.es/m/2444AA15-D21B-4CCE-8052-52C7C2DAFE5C%40amazon.com Backpatch-through: 12
* Fix the logical replication timeout during large transactions.Amit Kapila2022-05-11
| | | | | | | | | | | | | | | | | | | The problem is that we don't send keep-alive messages for a long time while processing large transactions during logical replication where we don't send any data of such transactions. This can happen when the table modified in the transaction is not published or because all the changes got filtered. We do try to send the keep_alive if necessary at the end of the transaction (via WalSndWriteData()) but by that time the subscriber-side can timeout and exit. To fix this we try to send the keepalive message if required after processing certain threshold of changes. Reported-by: Fabrice Chapuis Author: Wang wei and Amit Kapila Reviewed By: Masahiko Sawada, Euler Taveira, Hou Zhijie, Hayato Kuroda Backpatch-through: 10 Discussion: https://postgr.es/m/CAA5-nLARN7-3SLU_QUxfy510pmrYK6JJb=bk3hcgemAM_pAv+w@mail.gmail.com
* Error message refactoringPeter Eisentraut2021-06-27
| | | | | | Take some untranslatable things out of the message and replace by format placeholders, to reduce translatable strings and reduce translation mistakes.
* Revert recovery prefetching feature.Thomas Munro2021-05-10
| | | | | | | | | | | | | | | | | | This set of commits has some bugs with known fixes, but at this late stage in the release cycle it seems best to revert and resubmit next time, along with some new automated test coverage for this whole area. Commits reverted: dc88460c: Doc: Review for "Optionally prefetch referenced data in recovery." 1d257577: Optionally prefetch referenced data in recovery. f003d9f8: Add circular WAL decoding buffer. 323cbe7c: Remove read_page callback from XLogReader. Remove the new GUC group WAL_RECOVERY recently added by a55a9847, as the corresponding section of config.sgml is now reverted. Discussion: https://postgr.es/m/CAOuzzgrn7iKnFRsB4MHp3UisEQAGgZMbk_ViTN4HV4-Ksq8zCg%40mail.gmail.com
* Use HTAB for replication slot statistics.Amit Kapila2021-04-27
| | | | | | | | | | | | | | | | | | | | | | | Previously, we used to use the array of size max_replication_slots to store stats for replication slots. But that had two problems in the cases where a message for dropping a slot gets lost: 1) the stats for the new slot are not recorded if the array is full and 2) writing beyond the end of the array if the user reduces the max_replication_slots. This commit uses HTAB for replication slot statistics, resolving both problems. Now, pgstat_vacuum_stat() search for all the dead replication slots in stats hashtable and tell the collector to remove them. To avoid showing the stats for the already-dropped slots, pg_stat_replication_slots view searches slot stats by the slot name taken from pg_replication_slots. Also, we send a message for creating a slot at slot creation, initializing the stats. This reduces the possibility that the stats are accumulated into the old slot stats when a message for dropping a slot gets lost. Reported-by: Andres Freund Author: Sawada Masahiko, test case by Vignesh C Reviewed-by: Amit Kapila, Vignesh C, Dilip Kumar Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Add information of total data processed to replication slot stats.Amit Kapila2021-04-16
| | | | | | | | | | | | This adds the statistics about total transactions count and total transaction data logically sent to the decoding output plugin from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats. Suggested-by: Andres Freund Author: Vignesh C and Amit Kapila Reviewed-by: Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Use NameData datatype for slotname in stats.Amit Kapila2021-04-14
| | | | | | | | | | | This will make it consistent with the other usage of slotname in the code. In the passing, change pgstat_report_replslot signature to use a structure rather than multiple parameters. Reported-by: Andres Freund Author: Vignesh C Reviewed-by: Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Remove read_page callback from XLogReader.Thomas Munro2021-04-08
| | | | | | | | | | | | | | | | | | | | | Previously, the XLogReader module would fetch new input data using a callback function. Redesign the interface so that it tells the caller to insert more data with a special return value instead. This API suits later patches for prefetching, encryption and maybe other future projects that would otherwise require continually extending the callback interface. As incidental cleanup work, move global variables readOff, readLen and readSegNo inside XlogReaderState. Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> Author: Heikki Linnakangas <hlinnaka@iki.fi> (parts of earlier version) Reviewed-by: Antonin Houska <ah@cybertec.at> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Takashi Menjo <takashi.menjo@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/20190418.210257.43726183.horiguchi.kyotaro%40lab.ntt.co.jp
* Add a xid argument to the filter_prepare callback for output plugins.Amit Kapila2021-03-30
| | | | | | | | | | | | Along with gid, this provides a different way to identify the transaction. The users that use xid in some way to prepare the transactions can use it to filter prepare transactions. The later commands COMMIT PREPARED or ROLLBACK PREPARED carries both identifiers, providing an output plugin the choice of what to use. Author: Markus Wanner Reviewed-by: Vignesh C, Amit Kapila Discussion: https://postgr.es/m/ee280000-7355-c4dc-e47b-2436e7be959c@enterprisedb.com
* Add option to enable two_phase commits via pg_create_logical_replication_slot.Amit Kapila2021-03-03
| | | | | | | | | | | | | | | | | | | | Commit 0aa8a01d04 extends the output plugin API to allow decoding of prepared xacts and allowed the user to enable/disable the two-phase option via pg_logical_slot_get_changes(). This can lead to a problem such that the first time when it gets changes via pg_logical_slot_get_changes() without two_phase option enabled it will not get the prepared even though prepare is after consistent snapshot. Now next time during getting changes, if the two_phase option is enabled it can skip prepare because by that time start decoding point has been moved. So the user will only get commit prepared. Allow to enable/disable this option at the create slot time and default will be false. It will break the existing slots which is fine in a major release. Author: Ajin Cherian Reviewed-by: Amit Kapila and Vignesh C Discussion: https://postgr.es/m/d0f60d60-133d-bf8d-bd70-47784d8fabf3@enterprisedb.com
* Avoid repeated decoding of prepared transactions after a restart.Amit Kapila2021-03-01
| | | | | | | | | | | | | | | | | | | | In commit a271a1b50e, we allowed decoding at prepare time and the prepare was decoded again if there is a restart after decoding it. It was done that way because we can't distinguish between the cases where we have not decoded the prepare because it was prior to consistent snapshot or we have decoded it earlier but restarted. To distinguish between these two cases, we have introduced an initial_consistent_point at the slot level which is an LSN at which we found a consistent point at the time of slot creation. This is also the point where we have exported a snapshot for the initial copy. So, prepare transaction prior to this point are sent along with commit prepared. This commit bumps SNAPBUILD_VERSION because of change in SnapBuild. It will break existing slots which is fine in a major release. Author: Ajin Cherian, based on idea by Andres Freund Reviewed-by: Amit Kapila and Vignesh C Discussion: https://postgr.es/m/d0f60d60-133d-bf8d-bd70-47784d8fabf3@enterprisedb.com
* Simplify printing of LSNsPeter Eisentraut2021-02-23
| | | | | | | | | | Add a macro LSN_FORMAT_ARGS for use in printf-style printing of LSNs. Convert all applicable code to use it. Reviewed-by: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/CAExHW5ub5NaTELZ3hJUCE6amuvqAtsSxc7O+uK7y4t9Rrk23cw@mail.gmail.com
* Fix typos in decode.c and logical.c.Amit Kapila2021-01-06
| | | | | Per report by Ajin Cherian in email: https://postgr.es/m/CAFPTHDYnRKDvzgDxoMn_CKqXA-D0MtrbyJvfvjBsO4G=UHDXkg@mail.gmail.com
* Allow decoding at prepare time in ReorderBuffer.Amit Kapila2021-01-04
| | | | | | | | | | | | | | | | | | | | | | | This patch allows PREPARE-time decoding of two-phase transactions (if the output plugin supports this capability), in which case the transactions are replayed at PREPARE and then committed later when COMMIT PREPARED arrives. Now that we decode the changes before the commit, the concurrent aborts may cause failures when the output plugin consults catalogs (both system and user-defined). We detect such failures with a special sqlerrcode ERRCODE_TRANSACTION_ROLLBACK introduced by commit 7259736a6e and stop decoding the remaining changes. Then we rollback the changes when rollback prepared is encountered. Author: Ajin Cherian and Amit Kapila based on previous work by Nikhil Sontakke and Stas Kelvich Reviewed-by: Amit Kapila, Peter Smith, Sawada Masahiko, Arseny Sher, and Dilip Kumar Tested-by: Takamichi Osumi Discussion: https://postgr.es/m/02DA5F5E-CECE-4D9C-8B4B-418077E2C010@postgrespro.ru https://postgr.es/m/CAMGcDxeqEpWj3fTXwqhSwBdXd2RS9jzwWscO-XbeCfso6ts3+Q@mail.gmail.com
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Extend the output plugin API to allow decoding of prepared xacts.Amit Kapila2020-12-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds six methods to the output plugin API, adding support for streaming changes of two-phase transactions at prepare time. * begin_prepare * filter_prepare * prepare * commit_prepared * rollback_prepared * stream_prepare Most of this is a simple extension of the existing methods, with the semantic difference that the transaction is not yet committed and maybe aborted later. Until now two-phase transactions were translated into regular transactions on the subscriber, and the GID was not forwarded to it. None of the two-phase commands were communicated to the subscriber. This patch provides the infrastructure for logical decoding plugins to be informed of two-phase commands Like PREPARE TRANSACTION, COMMIT PREPARED and ROLLBACK PREPARED commands with the corresponding GID. This also extends the 'test_decoding' plugin, implementing these new methods. This commit simply adds these new APIs and the upcoming patch to "allow the decoding at prepare time in ReorderBuffer" will use these APIs. Author: Ajin Cherian and Amit Kapila based on previous work by Nikhil Sontakke and Stas Kelvich Reviewed-by: Amit Kapila, Peter Smith, Sawada Masahiko, and Dilip Kumar Discussion: https://postgr.es/m/02DA5F5E-CECE-4D9C-8B4B-418077E2C010@postgrespro.ru https://postgr.es/m/CAMGcDxeqEpWj3fTXwqhSwBdXd2RS9jzwWscO-XbeCfso6ts3+Q@mail.gmail.com
* Restore lock level to update statusFlagsAlvaro Herrera2020-11-26
| | | | | | | | | | | | | | Reverts 27838981be9d (some comments are kept). Per discussion, it does not seem safe to relax the lock level used for this; in order for it to be safe, there would have to be memory barriers between the point we set the flag and the point we set the trasaction Xid, which perhaps would not be so bad; but there would also have to be barriers at the readers' side, which from a performance perspective might be bad. Now maybe this analysis is wrong and it *is* safe for some reason, but proof of that is not trivial. Discussion: https://postgr.es/m/20201118190928.vnztes7c2sldu43a@alap3.anarazel.de
* Relax lock level for setting PGPROC->statusFlagsAlvaro Herrera2020-11-18
| | | | | | | | | | | | | | | | | | | We don't actually need a lock to set PGPROC->statusFlags itself; what we do need is a shared lock on either XidGenLock or ProcArrayLock in order to ensure MyProc->pgxactoff keeps still while we modify the mirror array in ProcGlobal->statusFlags. Some places were using an exclusive lock for that, which is excessive. Relax those to use shared lock only. procarray.c has a couple of places with somewhat brittle assumptions about PGPROC changes: ProcArrayEndTransaction uses only shared lock, so it's permissible to change MyProc only. On the other hand, ProcArrayEndTransactionInternal also changes other procs, so it must hold exclusive lock. Add asserts to ensure those assumptions continue to hold. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20201117155501.GA13805@alvherre.pgsql
* Rename PGPROC->vacuumFlags to statusFlagsAlvaro Herrera2020-11-16
| | | | | | | | | | | | | | | | | | | | With more flags associated to a PGPROC entry that are not related to vacuum (currently existing or planned), the name "statusFlags" describes its purpose better. (The same is done to the mirroring PROC_HDR->vacuumFlags.) No functional changes in this commit. This was suggested first by Hari Babu Kommi in [1] and then by Michael Paquier at [2]. [1] https://postgr.es/m/CAJrrPGcsDC-oy1AhqH0JkXYa0Z2AgbuXzHPpByLoBGMxfOZMEQ@mail.gmail.com [2] https://postgr.es/m/20200820060929.GB3730@paquier.xyz Author: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20201116182446.qcg3o6szo2zookyr@localhost
* Track statistics for streaming of changes from ReorderBuffer.Amit Kapila2020-10-29
| | | | | | | | | | | | | | | | | | | This adds the statistics about transactions streamed to the decoding output plugin from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats and call pg_stat_reset_replication_slot to reset the stats of a particular slot. Users can pass NULL in pg_stat_reset_replication_slot to reset stats of all the slots. Commit 9868167500 has added the basic infrastructure to capture the stats of slot and this commit extends the statistics collector to track additional information about slots. Bump the catversion as we have added new columns in the catalog entry. Author: Ajin Cherian and Amit Kapila Reviewed-by: Sawada Masahiko and Dilip Kumar Discussion: https://postgr.es/m/CAA4eK1+chpEomLzgSoky-D31qev19AmECNiEAietPQUGEFhtVA@mail.gmail.com
* Fix typos in logical.c and reorderbuffer.c.Amit Kapila2020-10-09
| | | | | Reviewed-by: Sawada Masahiko Discussion: https://postgr.es/m/CAA4eK1K6zTpuqf_d7wXCBjo_EF0_B6Fz3Ecp71Vq18t=wG-nzg@mail.gmail.com
* Track statistics for spilling of changes from ReorderBuffer.Amit Kapila2020-10-08
| | | | | | | | | | | | | | | This adds the statistics about transactions spilled to disk from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats and call pg_stat_reset_replication_slot to reset the stats of a particular slot. Users can pass NULL in pg_stat_reset_replication_slot to reset stats of all the slots. This commit extends the statistics collector to track this information about slots. Author: Sawada Masahiko and Amit Kapila Reviewed-by: Amit Kapila and Dilip Kumar Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com
* snapshot scalability: Move PGXACT->vacuumFlags to ProcGlobal->vacuumFlags.Andres Freund2020-08-14
| | | | | | | | | | | | | Similar to the previous commit this increases the chance that data frequently needed by GetSnapshotData() stays in l2 cache. As we now take care to not unnecessarily write to ProcGlobal->vacuumFlags, there should be very few modifications to the ProcGlobal->vacuumFlags array. Author: Andres Freund <andres@anarazel.de> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-By: Thomas Munro <thomas.munro@gmail.com> Reviewed-By: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/20200301083601.ews6hz5dduc3w2se@alap3.anarazel.de
* Replace remaining StrNCpy() by strlcpy()Peter Eisentraut2020-08-10
| | | | | | | | | | | | | | | | | They are equivalent, except that StrNCpy() zero-fills the entire destination buffer instead of providing just one trailing zero. For all but a tiny number of callers, that's just overhead rather than being desirable. Remove StrNCpy() as it is now unused. In some cases, namestrcpy() is the more appropriate function to use. While we're here, simplify the API of namestrcpy(): Remove the return value, don't check for NULL input. Nothing was using that anyway. Also, remove a few unused name-related functions. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/44f5e198-36f6-6cdb-7fa9-60e34784daae%402ndquadrant.com
* Add some const decorationsPeter Eisentraut2020-08-08
|
* Implement streaming mode in ReorderBuffer.Amit Kapila2020-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of serializing the transaction to disk after reaching the logical_decoding_work_mem limit in memory, we consume the changes we have in memory and invoke stream API methods added by commit 45fdc9738b. However, sometimes if we have incomplete toast or speculative insert we spill to the disk because we can't generate the complete tuple and stream. And, as soon as we get the complete tuple we stream the transaction including the serialized changes. We can do this incremental processing thanks to having assignments (associating subxact with toplevel xacts) in WAL right away, and thanks to logging the invalidation messages at each command end. These features are added by commits 0bead9af48 and c55040ccd0 respectively. Now that we can stream in-progress transactions, the concurrent aborts may cause failures when the output plugin consults catalogs (both system and user-defined). We handle such failures by returning ERRCODE_TRANSACTION_ROLLBACK sqlerrcode from system table scan APIs to the backend or WALSender decoding a specific uncommitted transaction. The decoding logic on the receipt of such a sqlerrcode aborts the decoding of the current transaction and continue with the decoding of other transactions. We have ReorderBufferTXN pointer in each ReorderBufferChange by which we know which xact it belongs to. The output plugin can use this to decide which changes to discard in case of stream_abort_cb (e.g. when a subxact gets discarded). We also provide a new option via SQL APIs to fetch the changes being streamed. Author: Dilip Kumar, Tomas Vondra, Amit Kapila, Nikhil Sontakke Reviewed-by: Amit Kapila, Kuntal Ghosh, Ajin Cherian Tested-by: Neha Sharma, Mahendra Singh Thalor and Ajin Cherian Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
* Extend the logical decoding output plugin API with stream methods.Amit Kapila2020-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds seven methods to the output plugin API, adding support for streaming changes of large in-progress transactions. * stream_start * stream_stop * stream_abort * stream_commit * stream_change * stream_message * stream_truncate Most of this is a simple extension of the existing methods, with the semantic difference that the transaction (or subtransaction) is incomplete and may be aborted later (which is something the regular API does not really need to deal with). This also extends the 'test_decoding' plugin, implementing these new stream methods. The stream_start/start_stop are used to demarcate a chunk of changes streamed for a particular toplevel transaction. This commit simply adds these new APIs and the upcoming patch to "allow the streaming mode in ReorderBuffer" will use these APIs. Author: Tomas Vondra, Dilip Kumar, Amit Kapila Reviewed-by: Amit Kapila Tested-by: Neha Sharma and Mahendra Singh Thalor Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
* Fix instance of elog() called while holding a spinlockMichael Paquier2020-06-04
| | | | | | | | This broke the project rule to not call any complex code while a spinlock is held. Issue introduced by b89e151. Discussion: https://postgr.es/m/20200602.161518.1399689010416646074.horikyota.ntt@gmail.com Backpatch-through: 9.5
* Rework XLogReader callback systemAlvaro Herrera2020-05-08
| | | | | | | | | | | | | | | | | | | Code review for 0dc8ead46363, prompted by a bug closed by 91c40548d5f7. XLogReader's system for opening and closing segments had gotten too complicated, with callbacks being passed at both the XLogReaderAllocate level (read_page) as well as at the WALRead level (segment_open). This was confusing and hard to follow, so restructure things so that these callbacks are passed together at XLogReaderAllocate time, and add another callback to the set (segment_close) to make it a coherent whole. Also, ensure XLogReaderState is an argument to all the callbacks, so that they can grab at the ->private data if necessary. Document the whole arrangement more clearly. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://postgr.es/m/20200422175754.GA19858@alvherre.pgsql
* Fix consistency issues with replication slot copyAlvaro Herrera2020-03-17
| | | | | | | | | | | | | | | | | | | Commit 9f06d79ef831's replication slot copying failed to properly reserve the WAL that the slot is expecting to see during DecodingContextFindStartpoint (to set the confirmed_flush LSN), so concurrent activity could remove that WAL and cause the copy process to error out. But it doesn't actually *need* that WAL anyway: instead of running decode to find confirmed_flush, it can be copied from the source slot. Fix this by rearranging things to avoid DecodingContextFindStartpoint() (leaving the target slot's confirmed_flush_lsn to invalid), and set that up afterwards by copying from the target slot's value. Also ensure the source slot's confirmed_flush_lsn is valid. Reported-by: Arseny Sher Author: Masahiko Sawada, Arseny Sher Discussion: https://postgr.es/m/871rr3ohbo.fsf@ars-thinkpad
* Remove excess parens in ereport() callsAlvaro Herrera2020-01-30
| | | | | | | Cosmetic cleanup, not worth backpatching. Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql Reviewed-by: Tom Lane, Michael Paquier
* Refactor XLogReadRecord(), adding XLogBeginRead() function.Heikki Linnakangas2020-01-26
| | | | | | | | | | | | | | | | | | | | The signature of XLogReadRecord() required the caller to pass the starting WAL position as argument, or InvalidXLogRecPtr to continue reading at the end of previous record. That's slightly awkward to the callers, as most of them don't want to randomly jump around in the WAL stream, but start reading at one position and then read everything from that point onwards. Remove the 'RecPtr' argument and add a new function XLogBeginRead() to specify the starting position instead. That's more convenient for the callers. Also, xlogreader holds state that is reset when you change the starting position, so having a separate function for doing that feels like a more natural fit. This changes XLogFindNextRecord() function so that it doesn't reset the xlogreader's state to what it was before the call anymore. Instead, it positions the xlogreader to the found record, like XLogBeginRead(). Reviewed-by: Kyotaro Horiguchi, Alvaro Herrera Discussion: https://www.postgresql.org/message-id/5382a7a3-debe-be31-c860-cb810c08f366%40iki.fi
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Make the order of the header file includes consistent in backend modules.Amit Kapila2019-11-12
| | | | | | | | | | | Similar to commits 7e735035f2 and dddf4cdc33, this commit makes the order of header file inclusion consistent for backend modules. In the passing, removed a couple of duplicate inclusions. Author: Vignesh C Reviewed-by: Kuntal Ghosh and Amit Kapila Discussion: https://postgr.es/m/CALDaNm2Sznv8RR6Ex-iJO6xAdsxgWhCoETkaYX=+9DW3q0QCfA@mail.gmail.com
* Rework WAL-reading supporting structsAlvaro Herrera2019-09-24
| | | | | | | | | | | | | | The state-tracking of WAL reading in various places was pretty messy, mostly because the ancient physical-replication WAL reading code wasn't using the XLogReader abstraction. This led to some untidy code. Make it prettier by creating two additional supporting structs, WALSegmentContext and WALOpenSegment which keep track of WAL-reading state. This makes code cleaner, as well as supports more future cleanup. Author: Antonin Houska Reviewed-by: Álvaro Herrera and (older versions) Robert Haas Discussion: https://postgr.es/m/14984.1554998742@spoje.net
* Remove fmgr.h includes from headers that don't really need it.Andres Freund2019-08-16
| | | | | | | | | Most of the fmgr.h includes were obsoleted by 352a24a1f9d6f7d4abb1. A few others can be obsoleted using the underlying struct type in an implementation detail. Author: Andres Freund Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
* Fix many typos and inconsistenciesMichael Paquier2019-07-01
| | | | | Author: Alexander Lakhin Discussion: https://postgr.es/m/af27d1b3-a128-9d62-46e0-88f424397f44@gmail.com
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* Remove duplicate assignment when initializing logical decoder contextMichael Paquier2019-04-16
| | | | | | | | | The private data in the WAL reader is already getting set when allocating it. Author: Antonin Houska Reviewed-by: Tom Lane Discussion: https://postgr.es/m/30563.1555329094@localhost
* Add facility to copy replication slotsAlvaro Herrera2019-04-05
| | | | | | | | | | | | | | This allows the user to create duplicates of existing replication slots, either logical or physical, and even changing properties such as whether they are temporary or the output plugin used. There are multiple uses for this, such as initializing multiple replicas using the slot for one base backup; when doing investigation of logical replication issues; and to select a different output plugins. Author: Masahiko Sawada Reviewed-by: Michael Paquier, Andres Freund, Petr Jelinek Discussion: https://postgr.es/m/CAD21AoAm7XX8y_tOPP6j4Nzzch12FvA1wPqiO690RCk+uYVstg@mail.gmail.com
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Disallow starting server with insufficient wal_level for existing slot.Andres Freund2018-10-31
| | | | | | | | | | | | | | | | Previously it was possible to create a slot, change wal_level, and restart, even if the new wal_level was insufficient for the slot. That's a problem for both logical and physical slots, because the necessary WAL records are not generated. This removes a few tests in newer versions that, somewhat inexplicably, whether restarting with a too low wal_level worked (a buggy behaviour!). Reported-By: Joshua D. Drake Author: Andres Freund Discussion: https://postgr.es/m/20181029191304.lbsmhshkyymhw22w@alap3.anarazel.de Backpatch: 9.4-, where replication slots where introduced
* Fix logical replication slot initializationAlvaro Herrera2018-08-01
| | | | | | | | | | | | | | This was broken in commit 9c7d06d60680, which inadvertently gave the wrong value to fast_forward in one StartupDecodingContext call. Fix by flipping the value. Add a test for the obvious error, namely trying to initialize a replication slot with an nonexistent output plugin. While at it, move the CreateDecodingContext call earlier, so that any errors are reported before sending the CopyBoth message. Author: Dave Cramer <davecramer@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CADK3HHLVkeRe1v4P02-5hj55H3_yJg3AEtpXyEY5T3wuzO2jSg@mail.gmail.com
* Rewrite comments in replication slot advance implementationAlvaro Herrera2018-07-19
| | | | | | | | | | | | The code added by 9c7d06d60680 was a bit obscure; clarify that by rewriting the comments. Lack of clarity has already caused bugs, so it's a worthy goal. Co-authored-by: Arseny Sher <a.sher@postgrespro.ru> Co-authored-by: Michaël Paquier <michael@paquier.xyz> Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Petr Jelínek <petr.jelinek@2ndquadrant.com> Discussion: https://postgr.es/m/87y3fgoyrn.fsf@ars-thinkpad
* Correct function name in comment of logical decoding codeMichael Paquier2018-07-02
| | | | | | Reported-by: Dave Cramer Author: Euler Taveira Discussion: https://postgr.es/m/CADK3HHKnPGJDLhjOFBY6+70Wd14iEH8c2GKw7UrOuUHp_GNFrA@mail.gmail.com
* Fix and document lock handling for in-memory replication slot dataMichael Paquier2018-06-10
| | | | | | | | | | | | | | | | | | | | | | | | | | While debugging issues on HEAD for the new slot forwarding feature of Postgres 11, some monitoring of the code surrounding in-memory slot data has proved that the lock handling may cause inconsistent data to be read by read-only callers of slot functions, particularly pg_get_replication_slots() which fetches data for the system view pg_replication_slots, or modules looking directly at slot information. The code paths involved in those problems concern logical decoding initialization (down to 9.4) and WAL reservation for slots (new as of 10). A set of comments documenting all the lock handlings, particularly the dependency with LW locks for slots and the in_use flag as well as the internal mutex lock is added, based on a suggested by Simon Riggs. Some of the fixed code exists down to 9.4 where WAL decoding has been introduced, but as those race conditions are really unlikely going to happen as those concern code paths for slot and decoding creation, just fix the problem on HEAD. Author: Michael Paquier Discussion: https://postgr.es/m/20180528085747.GA27845@paquier.xyz
* Post-feature-freeze pgindent run.Tom Lane2018-04-26
| | | | Discussion: https://postgr.es/m/15719.1523984266@sss.pgh.pa.us
* Logical decoding of TRUNCATEPeter Eisentraut2018-04-07
| | | | | | | | | | | | | | Add a new WAL record type for TRUNCATE, which is only used when wal_level >= logical. (For physical replication, TRUNCATE is already replicated via SMGR records.) Add new callback for logical decoding output plugins to receive TRUNCATE actions. Author: Simon Riggs <simon@2ndquadrant.com> Author: Marco Nenciarini <marco.nenciarini@2ndquadrant.it> Author: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
* Improve style guideline compliance of assorted error-report messages.Tom Lane2018-03-22
| | | | | | | | | | | | Per the project style guide, details and hints should have leading capitalization and end with a period. On the other hand, errcontext should not be capitalized and should not end with a period. To support well formatted error contexts in dblink, extend dblink_res_error() to take a format+arguments rather than a hardcoded string. Daniel Gustafsson Discussion: https://postgr.es/m/B3C002C8-21A0-4F53-A06E-8CAB29FCF295@yesql.se