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path: root/src/backend/replication
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2023-08-25Reset the logical worker type while cleaning up other worker info.Amit Kapila
Commit 2a8b40e36 introduces the worker type field for logical replication workers, but forgot to reset the type when the worker exits. This can lead to recognizing a stopped worker as a valid logical replication worker. Fix it by resetting the worker type and additionally adding the safeguard to not use LogicalRepWorker until ->in_use is verified. Reported-by: Thomas Munro based on cfbot reports. Author: Hou Zhijie, Alvaro Herrera Reviewed-by: Amit Kapila Discussion: http://postgr.es/m/CA+hUKGK2RQh4LifVgBmkHsCYChP-65UwGXOmnCzYVa5aAt4GWg@mail.gmail.com
2023-08-24Fix lack of message pluralizationPeter Eisentraut
2023-08-24Fix the error message when failing to restore the snapshot.Amit Kapila
The SnapBuildRestoreContents() used a const value in the error message to indicate the size in bytes it was expecting to read from the serialized snapshot file. Fix it by reporting the size that was actually passed. Author: Hou Zhijie Reviewed-by: Amit Kapila Backpatch-through: 16 Discussion: http://postgr.es/m/OS0PR01MB5716D408364F7DF32221C08D941FA@OS0PR01MB5716.jpnprd01.prod.outlook.com
2023-08-22Introduce macros for protocol characters.Nathan Bossart
This commit introduces descriptively-named macros for the identifiers used in wire protocol messages. These new macros are placed in a new header file so that they can be easily used by third-party code. Author: Dave Cramer Reviewed-by: Alvaro Herrera, Tatsuo Ishii, Peter Smith, Robert Haas, Tom Lane, Peter Eisentraut, Michael Paquier Discussion: https://postgr.es/m/CADK3HHKbBmK-PKf1bPNFoMC%2BoBt%2BpD9PH8h5nvmBQskEHm-Ehw%40mail.gmail.com
2023-08-22Simplify the logical worker type checks by using the switch on worker type.Amit Kapila
The current code uses if/else statements at various places to take worker specific actions. Change those to use the switch on worker type added by commit 2a8b40e368. This makes code easier to read and understand. Author: Peter Smith Reviewed-by: Amit Kapila, Hou Zhijie Discussion: http://postgr.es/m/CAHut+PttPSuP0yoZ=9zLDXKqTJ=d0bhxwKaEaNcaym1XqcvDEg@mail.gmail.com
2023-08-14Simplify determining logical replication worker types.Amit Kapila
We deduce a LogicalRepWorker's type from the values of several different fields ('relid' and 'leader_pid') whenever logic needs to know it. In fact, the logical replication worker type is already known at the time of launching the LogicalRepWorker and it never changes for the lifetime of that process. Instead of deducing the type, it is simpler to just store it one time, and access it directly thereafter. Author: Peter Smith Reviewed-by: Amit Kapila, Bharath Rupireddy Discussion: http://postgr.es/m/CAHut+PttPSuP0yoZ=9zLDXKqTJ=d0bhxwKaEaNcaym1XqcvDEg@mail.gmail.com
2023-08-04Simplify some of the logical replication worker-type checks.Amit Kapila
Author: Peter Smith Reviewed-by: Hou Zhijie Discussion: http://postgr.es/m/CAHut+Pv-xkEpuPzbEJ=ZSi7Hp2RoGJf=VA-uDRxLi1KHSneFjg@mail.gmail.com
2023-08-03Refactor to split Apply and Tablesync Workers code.Amit Kapila
Both apply and tablesync workers were using ApplyWorkerMain() as entry point. As the name implies, ApplyWorkerMain() should be considered as the main function for apply workers. Tablesync worker's path was hidden and does not have enough in common to share the same main function with apply worker. Also, most of the code shared by both worker types is already combined in LogicalRepApplyLoop(). There is no need to combine the rest in ApplyWorkerMain() anymore. This patch introduces TablesyncWorkerMain() as a new entry point for tablesync workers. This aims to increase code readability and would help with future improvements like the reuse of tablesync workers in the initial synchronization. Author: Melih Mutlu based on suggestions by Melanie Plageman Reviewed-by: Peter Smith, Kuroda Hayato, Amit Kapila Discussion: http://postgr.es/m/CAGPVpCTq=rUDd4JUdaRc1XUWf4BrH2gdSNf3rtOMUGj9rPpfzQ@mail.gmail.com
2023-08-02Fix ReorderBufferCheckMemoryLimit() comment.Masahiko Sawada
Commit 7259736a6 updated the comment but it was not correct since ReorderBufferLargestStreamableTopTXN() returns only top-level transactions. Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CAD21AoA9XB7OR86BqvrCe2dMYX%2BZv3-BvVmjF%3DGY2z6jN-kqjg%40mail.gmail.com Backpatch-through: 14
2023-07-25Fix code indentation vioaltion introduced in commit d38ad8e31d.Amit Kapila
Per buildfarm member koel Discussion: https://postgr.es/m/ZL9bsGhthne6FaVV@paquier.xyz
2023-07-25Remove unnecessary checks for indexes for REPLICA IDENTITY FULL tables.Masahiko Sawada
Previously, when selecting an usable index for update/delete for the REPLICA IDENTITY FULL table, in IsIndexOnlyExpression(), we used to check if all index fields are not expressions. However, it was not necessary, because it is enough to check if only the leftmost index field is not an expression (and references the remote table column) and this check has already been done by RemoteRelContainsLeftMostColumnOnIdx(). This commit removes IsIndexOnlyExpression() and RemoteRelContainsLeftMostColumnOnIdx() and all checks for usable indexes for REPLICA IDENTITY FULL tables are now performed by IsIndexUsableForReplicaIdentityFull(). Backpatch this to remain the code consistent. Reported-by: Peter Smith Reviewed-by: Amit Kapila, Önder Kalacı Discussion: https://postgr.es/m/CAHut%2BPsGRE5WSsY0jcLHJEoA17MrbP9yy8FxdjC_ZOAACxbt%2BQ%40mail.gmail.com Backpatch-through: 16
2023-07-25Fix the display of UNKNOWN message type in apply worker.Amit Kapila
We include the message type while displaying an error context in the apply worker. Now, while retrieving the message type string if the message type is unknown we throw an error that will hide the original error. So, instead, we need to simply return the string indicating an unknown message type. Reported-by: Ashutosh Bapat Author: Euler Taveira, Amit Kapila Reviewed-by: Ashutosh Bapat Backpatch-through: 15 Discussion: https://postgr.es/m/CAExHW5suAEDW-mBZt_qu4RVxWZ1vL54-L+ci2zreYWebpzxYsA@mail.gmail.com
2023-07-14Allow the use of a hash index on the subscriber during replication.Amit Kapila
Commit 89e46da5e5 allowed using BTREE indexes that are neither PRIMARY KEY nor REPLICA IDENTITY on the subscriber during apply of update/delete. This patch extends that functionality to also allow HASH indexes. We explored supporting other index access methods as well but they don't have a fixed strategy for equality operation which is required by the current infrastructure in logical replication to scan the indexes. Author: Kuroda Hayato Reviewed-by: Peter Smith, Onder Kalaci, Amit Kapila Discussion: https://postgr.es/m/TYAPR01MB58669D7414E59664E17A5827F522A@TYAPR01MB5866.jpnprd01.prod.outlook.com
2023-07-13Fix untranslatable log message assemblyPeter Eisentraut
We can't inject the name of the logical replication worker into a log message like that. But for these messages we don't really need the precision of knowing what kind of worker it was, so just write "logical replication worker" and keep the message in one piece. Discussion: https://www.postgresql.org/message-id/flat/CAHut%2BPt1xwATviPGjjtJy5L631SGf3qjV9XUCmxLu16cHamfgg%40mail.gmail.com
2023-07-13Doc: clarify the conditions of usable indexes for REPLICA IDENTITY FULL tables.Masahiko Sawada
Commit 89e46da5e allowed REPLICA IDENTITY FULL tables to use an index on the subscriber during apply of update/delete. This commit clarifies in the documentation that the leftmost field of candidate indexes must be a column (not an expression) that references the published relation column. The source code comments are also updated accordingly. Reviewed-by: Peter Smith, Amit Kapila Discussion: https://postgr.es/m/CAD21AoDJjffEvUFKXT27Q5U8-UU9JHv4rrJ9Ke8Zkc5UPWHLvA@mail.gmail.com Backpatch-through: 16
2023-07-10Message wording improvementsPeter Eisentraut
2023-07-06Handle \v as a whitespace character in parsersMichael Paquier
This commit comes as a continuation of the discussion that has led to d522b05, as \v was handled inconsistently when parsing array values or anything going through the parsers, and changing a parser behavior in stable branches is a scary thing to do. The parsing of array values now uses the more central scanner_isspace() and array_isspace() is removed. As pointing out by Peter Eisentraut, fix a confusing reference to horizontal space in the parsers with the term "horiz_space". \f was included in this set since 3cfdd8f from 2000, but it is not horizontal. "horiz_space" is renamed to "non_newline_space", to refer to all whitespace characters except newlines. The changes impact the parsers for the backend, psql, seg, cube, ecpg and replication commands. Note that JSON should not escape \v, as per RFC 7159, so these are not touched. Reviewed-by: Peter Eisentraut, Tom Lane Discussion: https://postgr.es/m/ZJKcjNwWHHvw9ksQ@paquier.xyz
2023-07-05Change example in pgindent README on "/*-----" comments.Heikki Linnakangas
Most, but not all, of our "/*----" style comments have an end-guard line with dashes at the end of the comment. However, pgindent doesn't care about the end-guards, so they mostly just waste screen space. Going forward, let's not require end-guards. Remove a broken end-guard in a comment in walsender.c that led me to think about this. Remove the end guard from another comment in walsender.c for consistency, so that we use the same style in all comments in the file. However, we have thousands of existing "/*----" comments the repository, so it's not worth the code churn to change them all. Discussion: https://www.postgresql.org/message-id/fb083c91-d490-3b65-25f3-05e9118b6b0d%40iki.fi
2023-07-04Fix assertion failure in snapshot buildingDaniel Gustafsson
Clear any potential stale next_phase_at value from the snapshot builder which otherwise may trip an assertion check ensuring that there is no next_phase_at value. This can be reproduced by running 80 concurrent sessions like the below where $c is a loop counter (assumes there has been 1..$c databases created) : echo " CREATE TABLE replication_example(id SERIAL PRIMARY KEY, somedata int, text varchar(120)); SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_$c', 'test_decoding'); SELECT data FROM pg_logical_slot_get_changes('regression_slot_$c', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1'); " | psql -d regress_$c >>psql.log & Backpatch down to v16. Bug: #17695 Author: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Alexander Lakhin <exclusion@gmail.com> Reported-by: bowenshi <zxwsbg@qq.com> Discussion: https://postgr.es/m/17695-6be9277c9295985f@postgresql.org Backpatch-through: v16
2023-07-03Increase size of bgw_library_name.Nathan Bossart
This commit increases the size of the bgw_library_name member of the BackgroundWorker struct from BGW_MAXLEN (96) bytes to MAXPGPATH (default of 1024) bytes so that it can store longer file names (e.g., absolute paths). Author: Yurii Rashkovskii Reviewed-by: Daniel Gustafsson, Aleksander Alekseev Discussion: https://postgr.es/m/CA%2BRLCQyjFV5Y8tG5QgUb6gjteL4S3p%2B1gcyqWTqigyM93WZ9Pg%40mail.gmail.com
2023-06-30Remove redundant check for fast_forward.Heikki Linnakangas
We already checked for it earlier in the function. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/1ba2899e-77f8-7866-79e5-f3b7d1251a3e@iki.fi
2023-06-30Improve comment on why we need ctid->(cmin,cmax) mapping.Heikki Linnakangas
Combocids are only part of the problem. Explain the problem in more detail. Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/1ba2899e-77f8-7866-79e5-f3b7d1251a3e@iki.fi
2023-06-28Reword error messages for consistencyPeter Eisentraut
2023-06-23Error message refactoringPeter Eisentraut
Take some untranslatable things out of the message and replace by format placeholders, to reduce translatable strings and reduce translation mistakes.
2023-06-20Pre-beta2 mechanical code beautification.Tom Lane
Run pgindent and pgperltidy. It seems we're still some ways away from all committers doing this automatically. Now that we have a buildfarm animal that will whine about poorly-indented code, we'll try to keep the tree more tidy. Discussion: https://postgr.es/m/3156045.1687208823@sss.pgh.pa.us
2023-06-15Fix possible crash in tablesync worker.Amit Kapila
Commit c3afe8cf5a added a new password_required option but forgot that you need database access to check whether an arbitrary role ID is a superuser. Commit e7e7da2f8d fixed a similar bug in apply worker, and this patch fixes a similar bug in tablesync worker. Author: Hou Zhijie Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/OS0PR01MB571607F5A9D723755268D36294759@OS0PR01MB5716.jpnprd01.prod.outlook.com
2023-06-09Honor run_as_owner option in tablesync worker.Masahiko Sawada
Commit 482675987 introduced "run_as_owner" subscription option so that subscription runs with either the permissions of the subscription owner or the permission of the table owner. However, tablesync workers did not use this option for the initial data copy. With this change, tablesync workers run with appropriate permissions based on "run_as_owner" option. Ajin Cherian, with changes and regression tests added by me. Reported-By: Amit Kapila Author: Ajin Cherian, Masahiko Sawada Reviewed-by: Ajin Cherian, Amit Kapila Discussion: https://postgr.es/m/CAA4eK1L=qzRHPEn+qeMoKQGFBzqGoLBzt_ov0A89iFFiut+ppA@mail.gmail.com
2023-06-07Reload configuration more frequently in apply worker.Amit Kapila
The apply worker was not reloading the configuration while processing messages if there is a continuous flow of messages from upstream. It was also not reloading the configuration if there is a change in the configuration after it has waited for the message and before receiving the new replication message. This can lead to failure in tests because we expect that after reload, the behavior of apply worker to respect the changed GUCs. We found this while analyzing a rare buildfarm failure. Author: Hou Zhijie Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/OS0PR01MB5716AF9079CC0755CD015322947E9@OS0PR01MB5716.jpnprd01.prod.outlook.com
2023-05-21Optimize walsender wake up logic using condition variablesAndres Freund
WalSndWakeup() currently loops through all the walsenders slots, with a spinlock acquisition and release for every iteration, to wake up waiting walsenders. This commonly was not a problem before e101dfac3a53c. But, to allow logical decoding on standbys, we need to wake up logical walsenders after every WAL record is applied on the standby, rather just when flushing WAL or switching timelines. This causes a performance regression for workloads replaying a lot of WAL records. To solve this, we use condition variable (CV) to efficiently wake up walsenders in WalSndWakeup(). Every walsender prepares to sleep on a shared memory CV. Note that it just prepares to sleep on the CV (i.e., adds itself to the CV's waitlist), but does not actually wait on the CV (IOW, it never calls ConditionVariableSleep()). It still uses WaitEventSetWait() for waiting, because CV infrastructure doesn't handle FeBe socket events currently. The processes (startup process, walreceiver etc.) wanting to wake up walsenders use ConditionVariableBroadcast(), which in turn calls SetLatch(), helping walsenders come out of WaitEventSetWait(). We use separate shared memory CVs for physical and logical walsenders for selective wake ups, see WalSndWakeup() for more details. This approach is simple and reasonably efficient. But not very elegant. But for 16 it seems to be a better path than a larger redesign of the CV mechanism. A desirable future improvement would be to add support for CVs into WaitEventSetWait(). This still leaves us with a small regression in very extreme workloads (due to the spinlock acquisition in ConditionVariableBroadcast() when there are no waiters) - but that seems acceptable. Reported-by: Andres Freund <andres@anarazel.de> Suggested-by: Andres Freund <andres@anarazel.de> Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com> Discussion: https://www.postgresql.org/message-id/20230509190247.3rrplhdgem6su6cg%40awork3.anarazel.de
2023-05-19Pre-beta mechanical code beautification.Tom Lane
Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
2023-05-19Fix misbehavior of EvalPlanQual checks with multiple result relations.Tom Lane
The idea of EvalPlanQual is that we replace the query's scan of the result relation with a single injected tuple, and see if we get a tuple out, thereby implying that the injected tuple still passes the query quals. (In join cases, other relations in the query are still scanned normally.) This logic was not updated when commit 86dc90056 made it possible for a single DML query plan to have multiple result relations, when the query target relation has inheritance or partition children. We replaced the output for the current result relation successfully, but other result relations were still scanned normally; thus, if any other result relation contained a tuple satisfying the quals, we'd think the EPQ check passed, even if it did not pass for the injected tuple itself. This would lead to update or delete actions getting performed when they should have been skipped due to a conflicting concurrent update in READ COMMITTED isolation mode. Fix by blocking all sibling result relations from emitting tuples during an EvalPlanQual recheck. In the back branches, the fix is complicated a bit by the need to not change the size of struct EPQState (else we'd have ABI-breaking changes in offsets in struct ModifyTableState). Like the back-patches of 3f7836ff6 and 4b3e37993, add a separately palloc'd struct to avoid that. The logic is the same as in HEAD otherwise. This is only a live bug back to v14 where 86dc90056 came in. However, I chose to back-patch the test cases further, on the grounds that this whole area is none too well tested. I skipped doing so in v11 though because none of the test applied cleanly, and it didn't quite seem worth extra work for a branch with only six months to live. Per report from Ante Krešić (via Aleksander Alekseev) Discussion: https://postgr.es/m/CAJ7c6TMBTN3rcz4=AjYhLPD_w3FFT0Wq_C15jxCDn8U4tZnH1g@mail.gmail.com
2023-05-09Fix invalid memory access during the shutdown of the parallel apply worker.Amit Kapila
The callback function pa_shutdown() accesses MyLogicalRepWorker which may not be initialized if there is an error during the initialization of the parallel apply worker. The other problem is that by the time it is invoked even after the initialization of the worker, the MyLogicalRepWorker will be reset by another callback logicalrep_worker_onexit. So, it won't have the required information. To fix this, register the shutdown callback after we are attached to the worker slot. After this fix, we observed another issue which is that sometimes the leader apply worker tries to receive the message from the error queue that might already be detached by the parallel apply worker leading to an error. To prevent such an error, we ensure that the leader apply worker detaches from the parallel apply worker's error queue before stopping it. Reported-by: Sawada Masahiko Author: Hou Zhijie Reviewed-by: Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/CAD21AoDo+yUwNq6nTrvE2h9bB2vZfcag=jxWc7QxuWCmkDAqcA@mail.gmail.com
2023-05-03Fix assertion failure in apply worker.Amit Kapila
During exit, the logical replication apply worker tries to release session level locks, if any. However, if the apply worker exits due to an error before its connection is initialized, trying to release locks can lead to assertion failure. The locks will be acquired once the worker is initialized, so we don't need to release them till the worker initialization is complete. Reported-by: Alexander Lakhin Author: Hou Zhijie based on inputs from Sawada Masahiko and Amit Kapila Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/2185d65f-5aae-3efa-c48f-fb42b173ef5c@gmail.com
2023-05-02Fix typos in commentsMichael Paquier
The changes done in this commit impact comments with no direct user-visible changes, with fixes for incorrect function, variable or structure names. Author: Alexander Lakhin Discussion: https://postgr.es/m/e8c38840-596a-83d6-bd8d-cebc51111572@gmail.com
2023-04-24Use elog to report unexpected action in handle_streamed_transaction().Masahiko Sawada
An oversight in commit 216a784829c. Author: Masahiko Sawada Reviewed-by: Kyotaro Horiguchi, Amit Kapila Discussion: https://postgr.es/m/CAD21AoDDbM8_HJt-nMCvcjTK8K9hPzXWqJj7pyaUvR4mm_NrSg@mail.gmail.com
2023-04-20Restart the apply worker if the 'password_required' option is changed.Amit Kapila
The apply worker is restarted if any subscription option that affects the remote connection was changed. In commit c3afe8cf5a, we added the option 'password_required' which can affect the remote connection, so we should restart the worker if it was changed. Author: Amit Kapila Reviewed-by: Robert Haas Discussion: https://postgr.es/m/CAA4eK1+z9UDFEynXLsWeMMuUZc1iQkRwj2HNDtxUHTPo-u1F4A@mail.gmail.com Discussion: https://postgr.es/m/9DFC88D3-1300-4DE8-ACBC-4CEF84399A53@enterprisedb.com
2023-04-19Fix various typos and incorrect/outdated name referencesDavid Rowley
Author: Alexander Lakhin Discussion: https://postgr.es/m/699beab4-a6ca-92c9-f152-f559caf6dc25@gmail.com
2023-04-18Fix some typos and some incorrectly duplicated wordsDavid Rowley
Author: Justin Pryzby Reviewed-by: David Rowley Discussion: https://postgr.es/m/ZD3D1QxoccnN8A1V@telsasoft.com
2023-04-12Improve error messages introduced in be87200efd9 and 0fdab27ad68Andres Freund
Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://postgr.es/m/20230411.120301.93333867350615278.horikyota.ntt@gmail.com Discussion: https://postgr.es/m/20230412174244.6njadz4uoiez3l74@awork3.anarazel.de
2023-04-08Allow logical decoding on standbysAndres Freund
Unsurprisingly, this requires wal_level = logical to be set on the primary and standby. The infrastructure added in 26669757b6a ensures that slots are invalidated if the primary's wal_level is lowered. Creating a slot on a standby waits for a xl_running_xact record to be processed. If the primary is idle (and thus not emitting xl_running_xact records), that can take a while. To make that faster, this commit also introduces the pg_log_standby_snapshot() function. By executing it on the primary, completion of slot creation on the standby can be accelerated. Note that logical decoding on a standby does not itself enforce that required catalog rows are not removed. The user has to use physical replication slots + hot_standby_feedback or other measures to prevent that. If catalog rows required for a slot are removed, the slot is invalidated. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion, for the addition of the pg_log_standby_snapshot() function. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Author: Andres Freund <andres@anarazel.de> (in an older version) Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version) Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: FabrÌzio de Royes Mello <fabriziomello@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-By: Robert Haas <robertmhaas@gmail.com>
2023-04-08For cascading replication, wake physical and logical walsenders separatelyAndres Freund
Physical walsenders can't send data until it's been flushed; logical walsenders can't decode and send data until it's been applied. On the standby, the WAL is flushed first, which will only wake up physical walsenders; and then applied, which will only wake up logical walsenders. Previously, all walsenders were awakened when the WAL was flushed. That was fine for logical walsenders on the primary; but on the standby the flushed WAL would have been not applied yet, so logical walsenders were awakened too early. Per idea from Jeff Davis and Amit Kapila. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-By: Jeff Davis <pgsql@j-davis.com> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/CAA4eK1+zO5LUeisabX10c81LU-fWMKO4M9Wyg1cdkbW7Hqh6vQ@mail.gmail.com
2023-04-08Handle logical slot conflicts on standbyAndres Freund
During WAL replay on the standby, when a conflict with a logical slot is identified, invalidate such slots. There are two sources of conflicts: 1) Using the information added in 6af1793954e, logical slots are invalidated if required rows are removed 2) wal_level on the primary server is reduced to below logical Uses the infrastructure introduced in the prior commit. FIXME: add commit reference. Change InvalidatePossiblyObsoleteSlot() to use a recovery conflict to interrupt use of a slot, if called in the startup process. The new recovery conflict is added to pg_stat_database_conflicts, as confl_active_logicalslot. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion for the addition of the pg_stat_database_conflicts column. Bumps PGSTAT_FILE_FORMAT_ID for the same reason. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Author: Andres Freund <andres@anarazel.de> Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version) Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
2023-04-07Support invalidating replication slots due to horizon and wal_levelAndres Freund
Needed for logical decoding on a standby. Slots need to be invalidated because of the horizon if rows required for logical decoding are removed. If the primary's wal_level is lowered from 'logical', logical slots on the standby need to be invalidated. The new invalidation methods will be used in a subsequent commit. Logical slots that have been invalidated can be identified via the new pg_replication_slots.conflicting column. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion for the addition of the new pg_replication_slots column. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Author: Andres Freund <andres@anarazel.de> Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version) Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
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
2023-04-07Replace replication slot's invalidated_at LSN with an enumAndres Freund
This is mainly useful because the upcoming logical-decoding-on-standby feature adds further reasons for invalidating slots, and we don't want to end up with multiple invalidated_* fields, or check different attributes. Eventually we should consider not resetting restart_lsn when invalidating a slot due to max_slot_wal_keep_size. But that's a user visible change, so left for later. Increases SLOT_VERSION, due to the changed field (with a different alignment, no less). Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
2023-04-04Add a run_as_owner option to subscriptions.Robert Haas
This option is normally false, but can be set to true to obtain the legacy behavior where the subscription runs with the permissions of the subscription owner rather than the permissions of the table owner. The advantages of this mode are (1) it doesn't require that the subscription owner have permission to SET ROLE to each table owner and (2) since no role switching occurs, the SECURITY_RESTRICTED_OPERATION restrictions do not apply. On the downside, it allows any table owner to easily usurp the privileges of the subscription owner - basically, to take over their account. Because that's generally quite undesirable, we don't make this mode the default, but we do make it available, just in case the new behavior causes too many problems for someone. Discussion: http://postgr.es/m/CA+TgmoZ-WEeG6Z14AfH7KhmpX2eFh+tZ0z+vf0=eMDdbda269g@mail.gmail.com
2023-04-04Perform logical replication actions as the table owner.Robert Haas
Up until now, logical replication actions have been performed as the subscription owner, who will generally be a superuser. Commit cec57b1a0fbcd3833086ba686897c5883e0a2afc documented hazards associated with that situation, namely, that any user who owns a table on the subscriber side could assume the privileges of the subscription owner by attaching a trigger, expression index, or some other kind of executable code to it. As a remedy, it suggested not creating configurations where users who are not fully trusted own tables on the subscriber. Although that will work, it basically precludes using logical replication in the way that people typically want to use it, namely, to replicate a database from one node to another without necessarily having any restrictions on which database users can own tables. So, instead, change logical replication to execute INSERT, UPDATE, DELETE, and TRUNCATE operations as the table owner when they are replicated. Since this involves switching the active user frequently within a session that is authenticated as the subscription user, also impose SECURITY_RESTRICTED_OPERATION restrictions on logical replication code. As an exception, if the table owner can SET ROLE to the subscription owner, these restrictions have no security value, so don't impose them in that case. Subscription owners are now required to have the ability to SET ROLE to every role that owns a table that the subscription is replicating. If they don't, replication will fail. Superusers, who normally own subscriptions, satisfy this property by default. Non-superusers users who own subscriptions will need to be granted the roles that own relevant tables. Patch by me, reviewed (but not necessarily in its entirety) by Jelte Fennema, Jeff Davis, and Noah Misch. Discussion: http://postgr.es/m/CA+TgmoaSCkg9ww9oppPqqs+9RVqCexYCE6Aq=UsYPfnOoDeFkw@mail.gmail.com
2023-04-03Fix possible logical replication crash.Robert Haas
Commit c3afe8cf5a1e465bd71e48e4bc717f5bfdc7a7d6 added a new password_required option but forgot that you need database access to check whether an arbitrary role ID is a superuser. Report and patch by Hou Zhijie. I added a comment. Thanks to Alexander Lakhin for devising a way to reproduce the crash. Discussion: http://postgr.es/m/OS0PR01MB5716BFD7EC44284C89F40808948F9@OS0PR01MB5716.jpnprd01.prod.outlook.com
2023-03-30Add new predefined role pg_create_subscription.Robert Haas
This role can be granted to non-superusers to allow them to issue CREATE SUBSCRIPTION. The non-superuser must additionally have CREATE permissions on the database in which the subscription is to be created. Most forms of ALTER SUBSCRIPTION, including ALTER SUBSCRIPTION .. SKIP, now require only that the role performing the operation own the subscription, or inherit the privileges of the owner. However, to use ALTER SUBSCRIPTION ... RENAME or ALTER SUBSCRIPTION ... OWNER TO, you also need CREATE permission on the database. This is similar to what we do for schemas. To change the owner of a schema, you must also have permission to SET ROLE to the new owner, similar to what we do for other object types. Non-superusers are required to specify a password for authentication and the remote side must use the password, similar to what is required for postgres_fdw and dblink. A superuser who wants a non-superuser to own a subscription that does not rely on password authentication may set the new password_required=false property on that subscription. A non-superuser may not set password_required=false and may not modify a subscription that already has password_required=false. This new password_required subscription property works much like the eponymous postgres_fdw property. In both cases, the actual semantics are that a password is not required if either (1) the property is set to false or (2) the relevant user is the superuser. Patch by me, reviewed by Andres Freund, Jeff Davis, Mark Dilger, and Stephen Frost (but some of those people did not fully endorse all of the decisions that the patch makes). Discussion: http://postgr.es/m/CA+TgmoaDH=0Xj7OBiQnsHTKcF2c4L+=gzPBUKSJLh8zed2_+Dg@mail.gmail.com
2023-03-30Refactor pgoutput_change().Amit Kapila
Instead of mostly-duplicate code for different operation (insert/update/delete) types, write a common code to compute old/new tuples, and check the row filter. Author: Hou Zhijie Reviewed-by: Peter Smith, Amit Kapila Discussion: https://postgr.es/m/OS0PR01MB5716194A47FFA8D91133687D94BF9@OS0PR01MB5716.jpnprd01.prod.outlook.com