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path: root/src/backend/replication/logical/logicalfuncs.c
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2024-03-08Introduce a new GUC 'standby_slot_names'.Amit Kapila
This patch provides a way to ensure that physical standbys that are potential failover candidates have received and flushed changes before the primary server making them visible to subscribers. Doing so guarantees that the promoted standby server is not lagging behind the subscribers when a failover is necessary. The logical walsender now guarantees that all local changes are sent and flushed to the standby servers corresponding to the replication slots specified in 'standby_slot_names' before sending those changes to the subscriber. Additionally, the SQL functions pg_logical_slot_get_changes, pg_logical_slot_peek_changes and pg_replication_slot_advance are modified to ensure that they process changes for failover slots only after physical slots specified in 'standby_slot_names' have confirmed WAL receipt for those. Author: Hou Zhijie and Shveta Malik Reviewed-by: Masahiko Sawada, Peter Smith, Bertrand Drouvot, Ajin Cherian, Nisha Moond, Amit Kapila Discussion: https://postgr.es/m/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com
2024-03-04Remove unused #include's from backend .c filesPeter Eisentraut
as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
2024-01-03Update copyright for 2024Bruce Momjian
Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
2023-10-18Add flush option to pg_logical_emit_message()Michael Paquier
Since its introduction, LogLogicalMessage() (via the SQL interface pg_logical_emit_message()) has never included a call to XLogFlush(), causing it to potentially lose messages on a crash when used in non-transactional mode. This has come up to me as a problem while playing with ideas to design a test suite for what has become 039_end_of_wal.pl introduced in bae868caf222 by Thomas Munro, because there are no direct ways to force a WAL flush via SQL. The default is false, to not flush messages and influence existing use-cases where this function could be used. If set to true, the message emitted is flushed before returning back to the caller, making the message durable on crash. This new option has no effect when using pg_logical_emit_message() in transactional mode, as the record's flush is guaranteed by the WAL record generated by the transaction committed. Two queries of test_decoding are tweaked to cover the new code path for the flush. Bump catalog version. Author: Michael Paquier Reviewed-by: Andres Freund, Amit Kapila, Fujii Masao, Tung Nguyen, Tomas Vondra Discussion: https://postgr.es/m/ZNsdThSe2qgsfs7R@paquier.xyz
2023-08-31Fix some shadow variables in src/backend/replication/Michael Paquier
The code is able to compile already without warnings under -Wshadow=compatible-local, which is itself already enabled in the tree, and the ones fixed here showed up with the more restrictive -Wshadow. There are more of these that we may want to look at, and the ones fixed here made the code confusing. Author: Peter Smith Discussion: https://postgr.es/m/CAHut+PuR0y4ofNOxi691VTVWmBfScHV9AaBMGSpeh8+DKp81Nw@mail.gmail.com
2023-04-07Prevent use of invalidated logical slot in CreateDecodingContext()Andres Freund
Previously we had checks for this in multiple places. Support for logical decoding on standbys will add other forms of invalidation, making it worth while to centralize the checks. This slightly changes the error message for both the walsender and SQL interface. Particularly the SQL interface error was inaccurate, as the "This slot has never previously reserved WAL" portion was unreachable. Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
2023-01-02Update copyright for 2023Bruce Momjian
Backpatch-through: 11
2022-10-18Rename SetSingleFuncCall() to InitMaterializedSRF()Michael Paquier
Per discussion, the existing routine name able to initialize a SRF function with materialize mode is unpopular, so rename it. Equally, the flags of this function are renamed, as of: - SRF_SINGLE_USE_EXPECTED -> MAT_SRF_USE_EXPECTED_DESC - SRF_SINGLE_BLESS -> MAT_SRF_BLESS The previous function and flags introduced in 9e98583 are kept around for compatibility purposes, so as any extension code already compiled with v15 continues to work as-is. The declarations introduced here for compatibility will be removed from HEAD in a follow-up commit. The new names have been suggested by Andres Freund and Melanie Plageman. Discussion: https://postgr.es/m/20221013194820.ciktb2sbbpw7cljm@awork3.anarazel.de Backpatch-through: 15
2022-07-01Add construct_array_builtin, deconstruct_array_builtinPeter Eisentraut
There were many calls to construct_array() and deconstruct_array() for built-in types, for example, when dealing with system catalog columns. These all hardcoded the type attributes necessary to pass to these functions. To simplify this a bit, add construct_array_builtin(), deconstruct_array_builtin() as wrappers that centralize this hardcoded knowledge. This simplifies many call sites and reduces the amount of hardcoded stuff that is spread around. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/2914356f-9e5f-8c59-2995-5997fc48bcba%40enterprisedb.com
2022-03-07Create routine able to set single-call SRFs for Materialize modeMichael Paquier
Set-returning functions that use the Materialize mode, creating a tuplestore to include all the tuples returned in a set rather than doing so in multiple calls, use roughly the same set of steps to prepare ReturnSetInfo for this job: - Check if ReturnSetInfo supports returning a tuplestore and if the materialize mode is enabled. - Create a tuplestore for all the tuples part of the returned set in the per-query memory context, stored in ReturnSetInfo->setResult. - Build a tuple descriptor mostly from get_call_result_type(), then stored in ReturnSetInfo->setDesc. Note that there are some cases where the SRF's tuple descriptor has to be the one specified by the function caller. This refactoring is done so as there are (well, should be) no behavior changes in any of the in-core functions refactored, and the centralized function that checks and sets up the function's ReturnSetInfo can be controlled with a set of bits32 options. Two of them prove to be necessary now: - SRF_SINGLE_USE_EXPECTED to use expectedDesc as tuple descriptor, as expected by the function's caller. - SRF_SINGLE_BLESS to validate the tuple descriptor for the SRF. The same initialization pattern is simplified in 28 places per my count as of src/backend/, shaving up to ~900 lines of code. These mostly come from the removal of the per-query initializations and the sanity checks now grouped in a single location. There are more locations that could be simplified in contrib/, that are left for a follow-up cleanup. fcc2817, 07daca5 and d61a361 have prepared the areas of the code related to this change, to ease this refactoring. Author: Melanie Plageman, Michael Paquier Reviewed-by: Álvaro Herrera, Justin Pryzby Discussion: https://postgr.es/m/CAAKRu_azyd1Z3W_r7Ou4sorTjRCs+PxeHw1CWJeXKofkE6TuZg@mail.gmail.com
2022-02-26Fix typo in logicalfuncs.c.Amit Kapila
Author: Bharath Rupireddy Discussion: https://postgr.es/m/CALj2ACX1mVtw8LWEnZgnpPdk2bPFR1xX2ZN+8GfXCffyip_9=Q@mail.gmail.com
2022-02-17Remove all traces of tuplestore_donestoring() in the C codeMichael Paquier
This routine is a no-op since dd04e95 from 2003, with a macro kept around for compatibility purposes. This has led to the same code patterns being copy-pasted around for no effect, sometimes in confusing ways like in pg_logical_slot_get_changes_guts() from logical.c where the code was actually incorrect. This issue has been discussed on two different threads recently, so rather than living with this legacy, remove any uses of this routine in the C code to simplify things. The compatibility macro is kept to avoid breaking any out-of-core modules that depend on it. Reported-by: Tatsuhito Kasahara, Justin Pryzby Author: Tatsuhito Kasahara Discussion: https://postgr.es/m/20211217200419.GQ17618@telsasoft.com Discussion: https://postgr.es/m/CAP0=ZVJeeYfAeRfmzqAF2Lumdiv4S4FewyBnZd4DPTrsSQKJKw@mail.gmail.com
2022-02-16Split xlog.c into xlog.c and xlogrecovery.c.Heikki Linnakangas
This moves the functions related to performing WAL recovery into the new xlogrecovery.c source file, leaving xlog.c responsible for maintaining the WAL buffers, coordinating the startup and switch from recovery to normal operations, and other miscellaneous stuff that have always been in xlog.c. Reviewed-by: Andres Freund, Kyotaro Horiguchi, Robert Haas Discussion: https://www.postgresql.org/message-id/a31f27b4-a31d-f976-6217-2b03be646ffa%40iki.fi
2022-01-25Fix various typos, grammar and code style in comments and docsMichael Paquier
This fixes a set of issues that have accumulated over the past months (or years) in various code areas. Most fixes are related to some recent additions, as of the development of v15. Author: Justin Pryzby Discussion: https://postgr.es/m/20220124030001.GQ23027@telsasoft.com
2022-01-07Update copyright for 2022Bruce Momjian
Backpatch-through: 10
2021-11-10Improve error messages for some callers of XLogReadRecord()Michael Paquier
A couple of code paths related to logical decoding (WAL sender, slot advancing, etc.) use XLogReadRecord(), feeding on error messages generated by walreader.c on a failure. All those messages have no context, making it harder to spot from where an error could come even if these should not happen. All the other callers of XLogReadRecord() do that already. Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/YYnTH6OyOwQcAdkw@paquier.xyz
2021-11-05Remove all use of ThisTimeLineID global variable outside of xlog.cRobert Haas
All such code deals with this global variable in one of three ways. Sometimes the same functions use it in more than one of these ways at the same time. First, sometimes it's an implicit argument to one or more functions being called in xlog.c or elsewhere, and must be set to the appropriate value before calling those functions lest they misbehave. In those cases, it is now passed as an explicit argument instead. Second, sometimes it's used to obtain the current timeline after the end of recovery, i.e. the timeline to which WAL is being written and flushed. Such code now calls GetWALInsertionTimeLine() or relies on the new out parameter added to GetFlushRecPtr(). Third, sometimes it's used during recovery to store the current replay timeline. That can change, so such code must generally update the value before each use. It can still do that, but must now use a local variable instead. The net effect of these changes is to reduce by a fair amount the amount of code that is directly accessing this global variable. That's good, because history has shown that we don't always think clearly about which timeline ID it's supposed to contain at any given point in time, or indeed, whether it has been or needs to be initialized at any given point in the code. Patch by me, reviewed and tested by Michael Paquier, Amul Sul, and Álvaro Herrera. Discussion: https://postgr.es/m/CA+TgmobfAAqhfWa1kaFBBFvX+5CjM=7TE=n4r4Q1o2bjbGYBpA@mail.gmail.com
2021-11-05Don't set ThisTimeLineID when there's no reason to do so.Robert Haas
In slotfuncs.c, pg_replication_slot_advance() needs to determine the LSN up to which the slot should be advanced, but that doesn't require us to update ThisTimeLineID, because none of the code called from here depends on it. If the replication slot is logical, pg_logical_replication_slot_advance will call read_local_xlog_page, which does use ThisTimeLineID, but also takes care of making sure it's up to date. If the replication slot is physical, the timeline isn't used for anything at all. In logicalfuncs.c, pg_logical_slot_get_changes_guts() has the same issue: the only code we're going to run that cares about timelines is in or downstream of read_local_xlog_page, which already makes sure that the correct value gets set. Hence, don't do it here. Patch by me, reviewed and tested by Michael Paquier, Amul Sul, and Álvaro Herrera. Discussion: https://postgr.es/m/CA+TgmobfAAqhfWa1kaFBBFvX+5CjM=7TE=n4r4Q1o2bjbGYBpA@mail.gmail.com
2021-09-14Remove code duplication for permission checks with replication slotsMichael Paquier
Two functions, both named check_permissions(), used the same checks to verify if a user had required privileges to work on replication slots. This commit removes the duplication, and moves the function doing the checks to slot.c to be centralized. Author: Bharath Rupireddy Reviewed-by: Nathan Bossart, Euler Taveira Discussion: https://postgr.es/m/CALj2ACUPpVw1u7sQocFVWrSs0n10pt_G_4NPZKSxXK6cW1dErw@mail.gmail.com
2021-06-11Return ReplicationSlotAcquire API to its original formAlvaro Herrera
Per 96540f80f833; the awkward API introduced by c6550776394e is no longer needed. Author: Andres Freund <andres@anarazel.de> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20210408020913.zzprrlvqyvlt5cyy@alap3.anarazel.de
2021-05-10Revert recovery prefetching feature.Thomas Munro
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
2021-04-08Remove read_page callback from XLogReader.Thomas Munro
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
2021-04-07Message improvementPeter Eisentraut
The previous wording contained a superfluous comma. Adjust phrasing for grammatical correctness and clarity.
2021-01-02Update copyright for 2021Bruce Momjian
Backpatch-through: 9.5
2020-05-08Rework XLogReader callback systemAlvaro Herrera
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
2020-04-28Check slot->restart_lsn validity in a few more placesAlvaro Herrera
Lack of these checks could cause visible misbehavior, including assertion failures. This was missed in commit c6550776394e, whereby restart_lsn becomes invalid when the size limit is exceeded. Also reword some existing error messages, and add errdetail(), so that the reported errors all match in spirit. Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20200408.093710.447591748588426656.horikyota.ntt@gmail.com
2020-04-07Allow users to limit storage reserved by replication slotsAlvaro Herrera
Replication slots are useful to retain data that may be needed by a replication system. But experience has shown that allowing them to retain excessive data can lead to the primary failing because of running out of space. This new feature allows the user to configure a maximum amount of space to be reserved using the new option max_slot_wal_keep_size. Slots that overrun that space are invalidated at checkpoint time, enabling the storage to be released. Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20170228.122736.123383594.horiguchi.kyotaro@lab.ntt.co.jp
2020-03-17Remove logical_read_local_xlog_pageAlvaro Herrera
It devolved into a content-less wrapper over read_local_xlog_page, with nothing to add, plus it's easily confused with walsender's logical_read_xlog_page. There doesn't seem to be any reason for it to stay. src/include/replication/logicalfuncs.h becomes empty, so remove it too. The prototypes it initially had were absorbed by generated fmgrprotos.h. Discussion: https://postgr.es/m/20191115214102.GA15616@alvherre.pgsql
2020-03-04Introduce macros for typalign and typstorage constants.Tom Lane
Our usual practice for "poor man's enum" catalog columns is to define macros for the possible values and use those, not literal constants, in C code. But for some reason lost in the mists of time, this was never done for typalign/attalign or typstorage/attstorage. It's never too late to make it better though, so let's do that. The reason I got interested in this right now is the need to duplicate some uses of the TYPSTORAGE constants in an upcoming ALTER TYPE patch. But in general, this sort of change aids greppability and readability, so it's a good idea even without any specific motivation. I may have missed a few places that could be converted, and it's even more likely that pending patches will re-introduce some hard-coded references. But that's not fatal --- there's no expectation that we'd actually change any of these values. We can clean up stragglers over time. Discussion: https://postgr.es/m/16457.1583189537@sss.pgh.pa.us
2020-01-30Clean up newlines following left parenthesesAlvaro Herrera
We used to strategically place newlines after some function call left parentheses to make pgindent move the argument list a few chars to the left, so that the whole line would fit under 80 chars. However, pgindent no longer does that, so the newlines just made the code vertically longer for no reason. Remove those newlines, and reflow some of those lines for some extra naturality. Reviewed-by: Michael Paquier, Tom Lane Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
2020-01-30Remove excess parens in ereport() callsAlvaro Herrera
Cosmetic cleanup, not worth backpatching. Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql Reviewed-by: Tom Lane, Michael Paquier
2020-01-26Refactor XLogReadRecord(), adding XLogBeginRead() function.Heikki Linnakangas
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
2020-01-01Update copyrights for 2020Bruce Momjian
Backpatch-through: update all files in master, backpatch legal files through 9.4
2019-11-12Make the order of the header file includes consistent in backend modules.Amit Kapila
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
2019-09-24Rework WAL-reading supporting structsAlvaro Herrera
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
2019-01-02Update copyright for 2019Bruce Momjian
Backpatch-through: certain files through 9.4
2018-07-18Use a ResourceOwner to track buffer pins in all cases.Tom Lane
Historically, we've allowed auxiliary processes to take buffer pins without tracking them in a ResourceOwner. However, that creates problems for error recovery. In particular, we've seen multiple reports of assertion crashes in the startup process when it gets an error while holding a buffer pin, as for example if it gets ENOSPC during a write. In a non-assert build, the process would simply exit without releasing the pin at all. We've gotten away with that so far just because a failure exit of the startup process translates to a database crash anyhow; but any similar behavior in other aux processes could result in stuck pins and subsequent problems in vacuum. To improve this, institute a policy that we must *always* have a resowner backing any attempt to pin a buffer, which we can enforce just by removing the previous special-case code in resowner.c. Add infrastructure to make it easy to create a process-lifespan AuxProcessResourceOwner and clear out its contents at appropriate times. Replace existing ad-hoc resowner management in bgwriter.c and other aux processes with that. (Thus, while the startup process gains a resowner where it had none at all before, some other aux process types are replacing an ad-hoc resowner with this code.) Also use the AuxProcessResourceOwner to manage buffer pins taken during StartupXLOG and ShutdownXLOG, even when those are being run in a bootstrap process or a standalone backend rather than a true auxiliary process. In passing, remove some other ad-hoc resource owner creations that had gotten cargo-culted into various other places. As far as I can tell that was all unnecessary, and if it had been necessary it was incomplete, due to lacking any provision for clearing those resowners later. (Also worth noting in this connection is that a process that hasn't called InitBufferPoolBackend has no business accessing buffers; so there's more to do than just add the resowner if we want to touch buffers in processes not covered by this patch.) Although this fixes a very old bug, no back-patch, because there's no evidence of any significant problem in non-assert builds. Patch by me, pursuant to a report from Justin Pryzby. Thanks to Robert Haas and Kyotaro Horiguchi for reviews. Discussion: https://postgr.es/m/20180627233939.GA10276@telsasoft.com
2018-01-17Ability to advance replication slotsSimon Riggs
Ability to advance both physical and logical replication slots using a new user function pg_replication_slot_advance(). For logical advance that means records are consumed as fast as possible and changes are not given to output plugin for sending. Makes 2nd phase (after we reached SNAPBUILD_FULL_SNAPSHOT) of replication slot creation faster, especially when there are big transactions as the reorder buffer does not have to deal with data changes and does not have to spill to disk. Author: Petr Jelinek Reviewed-by: Simon Riggs
2018-01-02Update copyright for 2018Bruce Momjian
Backpatch-through: certain files through 9.3
2017-07-25Fix race conditions in replication slot operationsAlvaro Herrera
It is relatively easy to get a replication slot to look as still active while one process is in the process of getting rid of it; when some other process tries to "acquire" the slot, it would fail with an error message of "replication slot XYZ is active for PID N". The error message in itself is fine, except that when the intention is to drop the slot, it is unhelpful: the useful behavior would be to wait until the slot is no longer acquired, so that the drop can proceed. To implement this, we use a condition variable so that slot acquisition can be told to wait on that condition variable if the slot is already acquired, and we make any change in active_pid broadcast a signal on the condition variable. Thus, as soon as the slot is released, the drop will proceed properly. Reported by: Tom Lane Discussion: https://postgr.es/m/11904.1499039688@sss.pgh.pa.us Authors: Petr Jelínek, Álvaro Herrera
2017-06-21Phase 3 of pgindent updates.Tom Lane
Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-05-17Post-PG 10 beta1 pgindent runBruce Momjian
perltidy run not included.
2017-05-12Lag tracking for logical replicationSimon Riggs
Lag tracking is called for each commit, but we introduce a pacing delay to ensure we don't swamp the lag tracker. Author: Petr Jelinek, with minor pacing delay code from me
2017-03-22Teach xlogreader to follow timeline switchesSimon Riggs
Uses page-based mechanism to ensure we’re using the correct timeline. Tests are included to exercise the functionality using a cold disk-level copy of the master that's started up as a replica with slots intact, but the intended use of the functionality is with later features. Craig Ringer, reviewed by Simon Riggs and Andres Freund
2017-01-20Move some things from builtins.h to new header filesPeter Eisentraut
This avoids that builtins.h has to include additional header files.
2017-01-03Update copyright via script for 2017Bruce Momjian
2016-09-06Add location field to DefElemPeter Eisentraut
Add a location field to the DefElem struct, used to parse many utility commands. Update various error messages to supply error position information. To propogate the error position information in a more systematic way, create a ParseState in standard_ProcessUtility() and pass that to interested functions implementing the utility commands. This seems better than passing the query string and then reassembling a parse state ad hoc, which violates the encapsulation of the ParseState type. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
2016-09-05Dirty replication slots when using sql interfaceSimon Riggs
When pg_logical_slot_get_changes(...) sets confirmed_flush_lsn to the point at which replay stopped, it doesn't dirty the replication slot. So if the replay didn't cause restart_lsn or catalog_xmin to change as well, this change will not get written out to disk. Even on a clean shutdown. If Pg crashes or restarts, a subsequent pg_logical_slot_get_changes(...) call will see the same changes already replayed since it uses the slot's confirmed_flush_lsn as the start point for fetching changes. The caller can't specify a start LSN when using the SQL interface. Mark the slot as dirty after reading changes using the SQL interface so that users won't see repeated changes after a clean shutdown. Repeated changes still occur when using the walsender interface or after an unclean shutdown. Craig Ringer
2016-05-04Revert timeline following in replication slotsAlvaro Herrera
This reverts commits f07d18b6e94d, 82c83b337202, 3a3b309041b0, and 24c5f1a103ce. This feature has shown enough immaturity that it was deemed better to rip it out before rushing some more fixes at the last minute. There are discussions on larger changes in this area for the next release.
2016-05-02Fix code comments regarding logical decodingAlvaro Herrera
Back in 3b02ea4f0780 I added some comments in various places to explain how logical decoding and other things worked. Not all of the changes were welcome, because they were misleading or wrong. This changes them a little bit to make them more accurate. Some other comments are also changed to be more accurate. Also, fix a bunch of typos. Author: Álvaro Herrera, Craig Ringer Andres Freund reviewed some parts of this.