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* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Introduce SYSTEM_USERMichael Paquier2022-09-29
| | | | | | | | | | | | | | | | | | | | | | | | SYSTEM_USER is a reserved keyword of the SQL specification that, roughly described, is aimed at reporting some information about the system user who has connected to the database server. It may include implementation-specific information about the means by the user connected, like an authentication method. This commit implements SYSTEM_USER as of auth_method:identity, where "auth_method" is a keyword about the authentication method used to log into the server (like peer, md5, scram-sha-256, gss, etc.) and "identity" is the authentication identity as introduced by 9afffcb (peer sets authn to the OS user name, gss to the user principal, etc.). This format has been suggested by Tom Lane. Note that thanks to d951052, SYSTEM_USER is available to parallel workers. Bump catalog version. Author: Bertrand Drouvot Reviewed-by: Jacob Champion, Joe Conway, Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/7e692b8c-0b11-45db-1cad-3afc5b57409f@amazon.com
* Mark ParallelMessagePending as sig_atomic_tMichael Paquier2022-09-27
| | | | | | | | | ParallelMessagePending was previously marked as a boolean which should be fine on modern platforms, but the C standard recommends the use of sig_atomic_t for variables manipulated in signal handlers. Author: Hayato Kuroda Discussion: https://postgr.es/m/TYAPR01MB58667C15A95A234720F4F876F5529@TYAPR01MB5866.jpnprd01.prod.outlook.com
* Allow parallel workers to retrieve some data from PortMichael Paquier2022-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | This commit moves authn_id into a new global structure called ClientConnectionInfo (mapping to a MyClientConnectionInfo for each backend) which is intended to hold all the client information that should be shared between the backend and any of its parallel workers, access for extensions and triggers being the primary use case. There is no need to push all the data of Port to the workers, and authn_id is quite a generic concept so using a separate structure provides the best balance (the name of the structure has been suggested by Robert Haas). While on it, and per discussion as this would be useful for a potential SYSTEM_USER that can be accessed through parallel workers, a second field is added for the authentication method, copied directly from Port. ClientConnectionInfo is serialized and restored using a new parallel key and a structure tracks the length of the authn_id, making the addition of more fields straight-forward. Author: Jacob Champion Reviewed-by: Bertrand Drouvot, Stephen Frost, Robert Haas, Tom Lane, Michael Paquier, Julien Rouhaud Discussion: https://postgr.es/m/793d990837ae5c06a558d58d62de9378ab525d83.camel@vmware.com
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Move parallel vacuum code to vacuumparallel.c.Amit Kapila2021-12-23
| | | | | | | | | | | | | | | This commit moves parallel vacuum related code to a new file commands/vacuumparallel.c so that any table AM supporting indexes can utilize parallel vacuum in order to call index AM callbacks (ambulkdelete and amvacuumcleanup) with parallel workers. Another reason for this refactoring is that the parallel vacuum isn't specific to heap so it doesn't make sense to keep this code in heap/vacuumlazy.c. Author: Masahiko Sawada, based on suggestion from Andres Freund Reviewed-by: Hou Zhijie, Amit Kapila, Haiying Tang Discussion: https://www.postgresql.org/message-id/20211030212101.ae3qcouatwmy7tbr%40alap3.anarazel.de
* Fix duplicate words in commentsDaniel Gustafsson2021-10-04
| | | | | | | Remove accidentally duplicated words in code comments. Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Discussion: https://postgr.es/m/87bl45t0co.fsf@wibble.ilmari.org
* Fix broken snapshot handling in parallel workers.Robert Haas2021-08-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Pengchengliu reported an assertion failure in a parallel woker while performing a parallel scan using an overflowed snapshot. The proximate cause is that TransactionXmin was set to an incorrect value. The underlying cause is incorrect snapshot handling in parallel.c. In particular, InitializeParallelDSM() was unconditionally calling GetTransactionSnapshot(), because I (rhaas) mistakenly thought that was always retrieving an existing snapshot whereas, at isolation levels less than REPEATABLE READ, it's actually taking a new one. So instead do this only at higher isolation levels where there actually is a single snapshot for the whole transaction. By itself, this is not a sufficient fix, because we still need to guarantee that TransactionXmin gets set properly in the workers. The easiest way to do that seems to be to install the leader's active snapshot as the transaction snapshot if the leader did not serialize a transaction snapshot. This doesn't affect the results of future GetTrasnactionSnapshot() calls since those have to take a new snapshot anyway; what we care about is the side effect of setting TransactionXmin. Report by Pengchengliu. Patch by Greg Nancarrow, except for some comment text which I supplied. Discussion: https://postgr.es/m/002f01d748ac$eaa781a0$bff684e0$@tju.edu.cn
* Make parallel worker shutdown complete entirely via before_shmem_exit().Andres Freund2021-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a step toward storing stats in dynamic shared memory. As dynamic shared memory segments are detached from just after before_shmem_exit() callbacks are processed, but before on_shmem_exit() callbacks are, no stats can be collected after before_shmem_exit() callbacks have been processed. Parallel worker shutdown can cause stats to be emitted during DSM detach callbacks, e.g. for SharedFileSet (which closes its files, which can causes fd.c to emit stats about temporary files). Therefore parallel worker shutdown needs to complete during the processing of before_shmem_exit callbacks. One might think this problem could instead be solved by carefully ordering the attaching to DSM segments, so that the pgstats segments get detached from later than the parallel query ones. That turns out to not work because the stats hash might need to grow which can cause new segments to be allocated, which then will be detached from earlier. There are two code changes: First, call ParallelWorkerShutdown() via before_shmem_exit. That's a good idea on its own, because other shutdown callbacks like ShutdownPostgres and ShutdownAuxiliaryProcess are called via before_*. Second, explicitly detach from the parallel query DSM segment, thereby ensuring all stats are emitted during ParallelWorkerShutdown(). There are nicer solutions to these problems, but it's not obvious which of those solutions is the correct one. As the shared memory stats work already is a huge amount of work... Author: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/20210405092914.mmxqe7j56lsjfsej@alap3.anarazel.de Discussion: https://postgr.es/m/20210803023612.iziacxk5syn2r4ut@alap3.anarazel.de
* Rename "enum blacklist" to "uncommitted enums".Thomas Munro2021-01-05
| | | | | | We agreed to remove this terminology and use something more descriptive. Discussion: https://postgr.es/m/20200615182235.x7lch5n6kcjq4aue%40alap3.anarazel.de
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* code: replace 'master' with 'leader' where appropriate.Andres Freund2020-07-08
| | | | | | | | | Leader already is the more widely used terminology, but a few places didn't get the message. Author: Andres Freund Reviewed-By: David Steele Discussion: https://postgr.es/m/20200615182235.x7lch5n6kcjq4aue@alap3.anarazel.de
* Comments and doc fixes for commit 40d964ec99.Amit Kapila2020-04-14
| | | | | | | Reported-by: Justin Pryzby Author: Justin Pryzby, with few changes by me Reviewed-by: Amit Kapila and Sawada Masahiko Discussion: https://postgr.es/m/20200322021801.GB2563@telsasoft.com
* Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch2020-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Bump XLOG_PAGE_MAGIC, since this introduces XLOG_GIST_ASSIGN_LSN. Future servers accept older WAL, so this bump is discretionary. Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
* Allow vacuum command to process indexes in parallel.Amit Kapila2020-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | This feature allows the vacuum to leverage multiple CPUs in order to process indexes. This enables us to perform index vacuuming and index cleanup with background workers. This adds a PARALLEL option to VACUUM command where the user can specify the number of workers that can be used to perform the command which is limited by the number of indexes on a table. Specifying zero as a number of workers will disable parallelism. This option can't be used with the FULL option. Each index is processed by at most one vacuum process. Therefore parallel vacuum can be used when the table has at least two indexes. The parallel degree is either specified by the user or determined based on the number of indexes that the table has, and further limited by max_parallel_maintenance_workers. The index can participate in parallel vacuum iff it's size is greater than min_parallel_index_scan_size. Author: Masahiko Sawada and Amit Kapila Reviewed-by: Dilip Kumar, Amit Kapila, Robert Haas, Tomas Vondra, Mahendra Singh and Sergei Kornilov Tested-by: Mahendra Singh and Prabhat Sahu Discussion: https://postgr.es/m/CAD21AoDTPMgzSkV4E3SFo1CH_x50bf5PqZFQf4jmqjk-C03BWg@mail.gmail.com https://postgr.es/m/CAA4eK1J-VoR9gzS5E75pcD-OH0mEyCdp8RihcwKrcuw7J-Q0+w@mail.gmail.com
* 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
* Enable parallel query with SERIALIZABLE isolation.Thomas Munro2019-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the SERIALIZABLE isolation level prevented parallel query from being used. Allow the two features to be used together by sharing the leader's SERIALIZABLEXACT with parallel workers. An extra per-SERIALIZABLEXACT LWLock is introduced to make it safe to share, and new logic is introduced to coordinate the early release of the SERIALIZABLEXACT required for the SXACT_FLAG_RO_SAFE optimization, as follows: The first backend to observe the SXACT_FLAG_RO_SAFE flag (set by some other transaction) will 'partially release' the SERIALIZABLEXACT, meaning that the conflicts and locks it holds are released, but the SERIALIZABLEXACT itself will remain active because other backends might still have a pointer to it. Whenever any backend notices the SXACT_FLAG_RO_SAFE flag, it clears its own MySerializableXact variable and frees local resources so that it can skip SSI checks for the rest of the transaction. In the special case of the leader process, it transfers the SERIALIZABLEXACT to a new variable SavedSerializableXact, so that it can be completely released at the end of the transaction after all workers have exited. Remove the serializable_okay flag added to CreateParallelContext() by commit 9da0cc35, because it's now redundant. Author: Thomas Munro Reviewed-by: Haribabu Kommi, Robert Haas, Masahiko Sawada, Kevin Grittner Discussion: https://postgr.es/m/CAEepm=0gXGYhtrVDWOTHS8SQQy_=S9xo+8oCxGLWZAOoeJ=yzQ@mail.gmail.com
* Refactor planner's header files.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | | | Create a new header optimizer/optimizer.h, which exposes just the planner functions that can be used "at arm's length", without need to access Paths or the other planner-internal data structures defined in nodes/relation.h. This is intended to provide the whole planner API seen by most of the rest of the system; although FDWs still need to use additional stuff, and more thought is also needed about just what selfuncs.c should rely on. The main point of doing this now is to limit the amount of new #include baggage that will be needed by "planner support functions", which I expect to introduce later, and which will be in relevant datatype modules rather than anywhere near the planner. This commit just moves relevant declarations into optimizer.h from other header files (a couple of which go away because everything got moved), and adjusts #include lists to match. There's further cleanup that could be done if we want to decide that some stuff being exposed by optimizer.h doesn't belong in the planner at all, but I'll leave that for another day. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Add WL_EXIT_ON_PM_DEATH pseudo-event.Thomas Munro2018-11-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Users of the WaitEventSet and WaitLatch() APIs can now choose between asking for WL_POSTMASTER_DEATH and then handling it explicitly, or asking for WL_EXIT_ON_PM_DEATH to trigger immediate exit on postmaster death. This reduces code duplication, since almost all callers want the latter. Repair all code that was previously ignoring postmaster death completely, or requesting the event but ignoring it, or requesting the event but then doing an unconditional PostmasterIsAlive() call every time through its event loop (which is an expensive syscall on platforms for which we don't have USE_POSTMASTER_DEATH_SIGNAL support). Assert that callers of WaitLatchXXX() under the postmaster remember to ask for either WL_POSTMASTER_DEATH or WL_EXIT_ON_PM_DEATH, to prevent future bugs. The only process that doesn't handle postmaster death is syslogger. It waits until all backends holding the write end of the syslog pipe (including the postmaster) have closed it by exiting, to be sure to capture any parting messages. By using the WaitEventSet API directly it avoids the new assertion, and as a by-product it may be slightly more efficient on platforms that have epoll(). Author: Thomas Munro Reviewed-by: Kyotaro Horiguchi, Heikki Linnakangas, Tom Lane Discussion: https://postgr.es/m/CAEepm%3D1TCviRykkUb69ppWLr_V697rzd1j3eZsRMmbXvETfqbQ%40mail.gmail.com, https://postgr.es/m/CAEepm=2LqHzizbe7muD7-2yHUbTOoF7Q+qkSD5Q41kuhttRTwA@mail.gmail.com
* Relax transactional restrictions on ALTER TYPE ... ADD VALUE (redux).Thomas Munro2018-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally committed as 15bc038f (plus some follow-ups), this was reverted in 28e07270 due to a problem discovered in parallel workers. This new version corrects that problem by sending the list of uncommitted enum values to parallel workers. Here follows the original commit message describing the change: To prevent possibly breaking indexes on enum columns, we must keep uncommitted enum values from getting stored in tables, unless we can be sure that any such column is new in the current transaction. Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE from being executed at all in a transaction block, unless the target enum type had been created in the current transaction. This patch removes that restriction, and instead insists that an uncommitted enum value can't be referenced unless it belongs to an enum type created in the same transaction as the value. Per discussion, this should be a bit less onerous. It does require each function that could possibly return a new enum value to SQL operations to check this restriction, but there aren't so many of those that this seems unmaintainable. Author: Andrew Dunstan and Tom Lane, with parallel query fix by Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D0Ei7g6PaNTbcmAh9tCRahQrk%3Dr5ZWLD-jr7hXweYX3yg%40mail.gmail.com Discussion: https://postgr.es/m/4075.1459088427%40sss.pgh.pa.us
* Propagate xactStartTimestamp and stmtStartTimestamp to parallel workers.Tom Lane2018-10-06
| | | | | | | | | | | | | | | | | | | | | | Previously, a worker process would establish values for these based on its own start time. In v10 and up, this can trivially be shown to cause misbehavior of transaction_timestamp(), timestamp_in(), and related functions which are (perhaps unwisely?) marked parallel-safe. It seems likely that other behaviors might diverge from what happens in the parent as well. It's not as trivial to demonstrate problems in 9.6 or 9.5, but I'm sure it's still possible, so back-patch to all branches containing parallel worker infrastructure. In HEAD only, mark now() and statement_timestamp() as parallel-safe (other affected functions already were). While in theory we could still squeeze that change into v11, it doesn't seem important enough to force a last-minute catversion bump. Konstantin Knizhnik, whacked around a bit by me Discussion: https://postgr.es/m/6406dbd2-5d37-4cb6-6eb2-9c44172c7e7c@postgrespro.ru
* Defer restoration of libraries in parallel workers.Thomas Munro2018-09-20
| | | | | | | | | | | | | | | | | | | | | | Several users of extensions complained of crashes in parallel workers that turned out to be due to syscache access from their _PG_init() functions. Reorder the initialization of parallel workers so that libraries are restored after the caches are initialized, and inside a transaction. This was reported in bug #15350 and elsewhere. We don't consider it to be a bug: extensions shouldn't do that, because then they can't be used in shared_preload_libraries. However, it's a fairly obscure hazard and these extensions worked in practice before parallel query came along. So let's make it work. Later commits might add a warning message and eventually an error. Back-patch to 9.6, where parallel query landed. Author: Thomas Munro Reviewed-by: Amit Kapila Reported-by: Kieran McCusker, Jimmy Discussion: https://postgr.es/m/153512195228.1489.8545997741965926448%40wrigleys.postgresql.org
* Handle parallel index builds on mapped relations.Peter Geoghegan2018-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9da0cc35284, which introduced parallel CREATE INDEX, failed to propagate relmapper.c backend local cache state to parallel worker processes. This could result in parallel index builds against mapped catalog relations where the leader process (participating as a worker) scans the new, pristine relfilenode, while worker processes scan the obsolescent relfilenode. When this happened, the final index structure was typically not consistent with the owning table's structure. The final index structure could contain entries formed from both heap relfilenodes. Only rebuilds on mapped catalog relations that occur as part of a VACUUM FULL or CLUSTER could become corrupt in practice, since their mapped relation relfilenode swap is what allows the inconsistency to arise. On master, fix the problem by propagating the required relmapper.c backend state as part of standard parallel initialization (Cf. commit 29d58fd3). On v11, simply disallow builds against mapped catalog relations by deeming them parallel unsafe. Author: Peter Geoghegan Reported-By: "death lock" Reviewed-By: Tom Lane, Amit Kapila Bug: #15309 Discussion: https://postgr.es/m/153329671686.1405.18298309097348420351@wrigleys.postgresql.org Backpatch: 11-, where parallel CREATE INDEX was introduced.
* Use a ResourceOwner to track buffer pins in all cases.Tom Lane2018-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Remove dynamic_shared_memory_type=nonePeter Eisentraut2018-07-10
| | | | | | | | | PostgreSQL nowadays offers some kind of dynamic shared memory feature on all supported platforms. Having the choice of "none" prevents us from relying on DSM in core features. So this patch removes the choice of "none". Author: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
* Allow background workers to bypass datallowconnMagnus Hagander2018-04-05
| | | | | | | THis adds a "flags" field to the BackgroundWorkerInitializeConnection() and BackgroundWorkerInitializeConnectionByOid(). For now only one flag, BGWORKER_BYPASS_ALLOWCONN, is defined, which allows the worker to ignore datallowconn.
* Be more wary about shm_toc_lookup failure.Tom Lane2018-02-02
| | | | | | | | | | | | | | | | Commit 445dbd82a basically missed the point of commit d46633506, which was that we shouldn't allow shm_toc_lookup() failure to lead to a core dump or assertion crash, because the odds of such a failure should never be considered negligible. It's correct that we can't expect the PARALLEL_KEY_ERROR_QUEUE TOC entry to be there if we have no workers. But if we have no workers, we're not going to do anything in this function with the lookup result anyway, so let's just skip it. That lets the code use the easy-to-prove-safe noError=false case, rather than anything requiring effort to review. Back-patch to v10, like the previous commit. Discussion: https://postgr.es/m/3647.1517601675@sss.pgh.pa.us
* Support parallel btree index builds.Robert Haas2018-02-02
| | | | | | | | | | | | | | | | | | | | | | To make this work, tuplesort.c and logtape.c must also support parallelism, so this patch adds that infrastructure and then applies it to the particular case of parallel btree index builds. Testing to date shows that this can often be 2-3x faster than a serial index build. The model for deciding how many workers to use is fairly primitive at present, but it's better than not having the feature. We can refine it as we get more experience. Peter Geoghegan with some help from Rushabh Lathia. While Heikki Linnakangas is not an author of this patch, he wrote other patches without which this feature would not have been possible, and therefore the release notes should possibly credit him as an author of this feature. Reviewed by Claudio Freire, Heikki Linnakangas, Thomas Munro, Tels, Amit Kapila, me. Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com
* Add new function WaitForParallelWorkersToAttach.Robert Haas2018-02-02
| | | | | | | | | | | | | | | | Once this function has been called, we know that all workers have started and attached to their error queues -- so if any of them subsequently exit uncleanly, we'll be sure to throw an ERROR promptly. Otherwise, users of the ParallelContext machinery must be careful not to wait forever for a worker that has failed to start. Parallel query manages to work without needing this for reasons explained in new comments added by this patch, but it's a useful primitive for other parallel operations, such as the pending patch to make creating a btree index run in parallel. Amit Kapila, revised by me. Additional review by Peter Geoghegan. Discussion: http://postgr.es/m/CAA4eK1+e2MzyouF5bg=OtyhDSX+=Ao=3htN=T-r_6s3gCtKFiw@mail.gmail.com
* Report an ERROR if a parallel worker fails to start properly.Robert Haas2018-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 28724fd90d2f85a0573a8107b48abad062a86d83 fixed things so that if a background worker fails to start due to fork() failure or because it is terminated before startup succeeds, BGWH_STOPPED will be reported. However, that only helps if the code that uses the background worker machinery notices the change in status, and the code in parallel.c did not. To fix that, do two things. First, make sure that when a worker exits, it triggers the leader to read from error queues. That way, if a worker which has attached to an error queue exits uncleanly, the leader is sure to throw some error, either the contents of the ErrorResponse sent by the worker, or "lost connection to parallel worker" if it exited without sending one. To cover the case where the worker never starts up in the first place or exits before attaching to the error queue, the ParallelContext now keeps track of which workers have sent at least one message via the error queue. A worker which sends no messages by the time the parallel operation finishes will be checked to see whether it exited before attaching to the error queue; if so, a new error message, "parallel worker failed to initialize", will be reported. If not, we'll continue to wait until it either starts up and exits cleanly, starts up and exits uncleanly, or fails to start, and then take the appropriate action. Patch by me, reviewed by Amit Kapila. Discussion: http://postgr.es/m/CA+TgmoYnBgXgdTu6wk5YPdWhmgabYc9nY_pFLq=tB=FSLYkD8Q@mail.gmail.com
* Transfer state pertaining to pending REINDEX operations to workers.Robert Haas2018-01-19
| | | | | | | | | | | | This will allow the pending patch for parallel CREATE INDEX to work on system catalogs, and to provide the same level of protection against use of user indexes while they are being rebuilt that we have for non-parallel CREATE INDEX. Patch by me, reviewed by Peter Geoghegan. Discussion: http://postgr.es/m/CA+TgmoYN-YQU9JsGQcqFLovZ-C+Xgp1_xhJQad=cunGG-_p5gg@mail.gmail.com Discussion: http://postgr.es/m/CAH2-Wzkv4UNkXYhqQRqk-u9rS7h5c-4cCW+EqQ8K_WSeS43aZg@mail.gmail.com
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Fix ReinitializeParallelDSM to tolerate finding no error queues.Robert Haas2017-11-28
| | | | | | | | | | | | | | | | Commit d4663350646ca0c069a36d906155a0f7e3372eb7 changed things so that shm_toc_lookup would fail with an error rather than silently returning NULL in the hope that such failures would be reported in a useful way rather than via a system crash. However, it overlooked the fact that the lookup of PARALLEL_KEY_ERROR_QUEUE in ReinitializeParallelDSM is expected to fail when no DSM segment was created in the first place; in that case, we end up with a backend-private memory segment that still contains an entry for PARALLEL_KEY_FIXED but no others. Consequently a benign failure to initialize parallelism can escalate into an elog(ERROR); repair. Discussion: http://postgr.es/m/CA+Tgmob8LFw55DzH1QEREpBEA9RJ_W_amhBFCVZ6WMwUhVpOqg@mail.gmail.com
* Fix problems with the "role" GUC and parallel query.Robert Haas2017-10-29
| | | | | | | | | | Without this fix, dropping a role can sometimes result in parallel query failures in sessions that have used "SET ROLE" to assume the dropped role, even if that setting isn't active any more. Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me. Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
* Replace remaining uses of pq_sendint with pq_sendint{8,16,32}.Andres Freund2017-10-11
| | | | | | | pq_sendint() remains, so extension code doesn't unnecessarily break. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Add background worker typePeter Eisentraut2017-09-29
| | | | | | | | | | | | | | | | | Add bgw_type field to background worker structure. It is intended to be set to the same value for all workers of the same type, so they can be grouped in pg_stat_activity, for example. The backend_type column in pg_stat_activity now shows bgw_type for a background worker. The ps listing also no longer calls out that a process is a background worker but just show the bgw_type. That way, being a background worker is more of an implementation detail now that is not shown to the user. However, most log messages still refer to 'background worker "%s"'; otherwise constructing sensible and translatable log messages would become tricky. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
* Add support for coordinating record typmods among parallel workers.Andres Freund2017-09-14
| | | | | | | | | | | | | | | | | | | | | | Tuples can have type RECORDOID and a typmod number that identifies a blessed TupleDesc in a backend-private cache. To support the sharing of such tuples through shared memory and temporary files, provide a typmod registry in shared memory. To achieve that, introduce per-session DSM segments, created on demand when a backend first runs a parallel query. The per-session DSM segment has a table-of-contents just like the per-query DSM segment, and initially the contents are a shared record typmod registry and a DSA area to provide the space it needs to grow. State relating to the current session is accessed via a Session object reached through global variable CurrentSession that may require significant redesign further down the road as we figure out what else needs to be shared or remodelled. Author: Thomas Munro Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
* Clean up shm_mq cleanup.Tom Lane2017-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | The logic around shm_mq_detach was a few bricks shy of a load, because (contrary to the comments for shm_mq_attach) all it did was update the shared shm_mq state. That left us leaking a bit of process-local memory, but much worse, the on_dsm_detach callback for shm_mq_detach was still armed. That means that whenever we ultimately detach from the DSM segment, we'd run shm_mq_detach again for already-detached, possibly long-dead queues. This accidentally fails to fail today, because we only ever re-use a shm_mq's memory for another shm_mq, and multiple detach attempts on the last such shm_mq are fairly harmless. But it's gonna bite us someday, so let's clean it up. To do that, change shm_mq_detach's API so it takes a shm_mq_handle not the underlying shm_mq. This makes the callers simpler in most cases anyway. Also fix a few places in parallel.c that were just pfree'ing the handle structs rather than doing proper cleanup. Back-patch to v10 because of the risk that the revenant shm_mq_detach callbacks would cause a live bug sometime. Since this is an API change, it's too late to do it in 9.6. (We could make a variant patch that preserves API, but I'm not excited enough to do that.) Discussion: https://postgr.es/m/8670.1504192177@sss.pgh.pa.us
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | 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
* Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Clean up latch related code.Andres Freund2017-06-06
| | | | | | | | | | | | | | | | | | | | | | The larger part of this patch replaces usages of MyProc->procLatch with MyLatch. The latter works even early during backend startup, where MyProc->procLatch doesn't yet. While the affected code shouldn't run in cases where it's not initialized, it might get copied into places where it might. Using MyLatch is simpler and a bit faster to boot, so there's little point to stick with the previous coding. While doing so I noticed some weaknesses around newly introduced uses of latches that could lead to missed events, and an omitted CHECK_FOR_INTERRUPTS() call in worker_spi. As all the actual bugs are in v10 code, there doesn't seem to be sufficient reason to backpatch this. Author: Andres Freund Discussion: https://postgr.es/m/20170606195321.sjmenrfgl2nu6j63@alap3.anarazel.de https://postgr.es/m/20170606210405.sim3yl6vpudhmufo@alap3.anarazel.de Backpatch: -
* Don't be so trusting that shm_toc_lookup() will always succeed.Tom Lane2017-06-05
| | | | | | | | | | | | | | | | | | Given the possibility of race conditions and so on, it seems entirely unsafe to just assume that shm_toc_lookup() always finds the key it's looking for --- but that was exactly what all but one call site were doing. To fix, add a "bool noError" argument, similarly to what we have in many other functions, and throw an error on an unexpected lookup failure. Remove now-redundant Asserts that a rather random subset of call sites had. I doubt this will throw any light on buildfarm member lorikeet's recent failures, because if an unnoticed lookup failure were involved, you'd kind of expect a null-pointer-dereference crash rather than the observed symptom. But you never know ... and this is better coding practice even if it never catches anything. Discussion: https://postgr.es/m/9697.1496675981@sss.pgh.pa.us
* Ensure BackgroundWorker struct contents are well-defined.Tom Lane2017-04-16
| | | | | | | | Coverity complained because bgw.bgw_extra wasn't being filled in by ApplyLauncherRegister(). The most future-proof fix is to memset the whole BackgroundWorker struct to zeroes. While at it, let's apply the same coding rule to other places that set up BackgroundWorker structs; four out of five had the same or related issues.
* Avoid passing function pointers across process boundaries.Tom Lane2017-04-14
| | | | | | | | | | | | | | | | We'd already recognized that we can't pass function pointers across process boundaries for functions in loadable modules, since a shared library could get loaded at different addresses in different processes. But actually the practice doesn't work for functions in the core backend either, if we're using EXEC_BACKEND. This is the cause of recent failures on buildfarm member culicidae. Switch to passing a string function name in all cases. Something like this needs to be back-patched into 9.6, but let's see if the buildfarm likes it first. Petr Jelinek, with a bunch of basically-cosmetic adjustments by me Discussion: https://postgr.es/m/548f9c1d-eafa-e3fa-9da8-f0cc2f654e60@2ndquadrant.com
* Don't use bgw_main even to specify in-core bgworker entrypoints.Robert Haas2017-03-31
| | | | | | | | | | | | | | | On EXEC_BACKEND builds, this can fail if ASLR is in use. Backpatch to 9.5. On master, completely remove the bgw_main field completely, since there is no situation in which it is safe for an EXEC_BACKEND build. On 9.6 and 9.5, leave the field intact to avoid breaking things for third-party code that doesn't care about working under EXEC_BACKEND. Prior to 9.5, there are no in-core bgworker entrypoints. Petr Jelinek, reviewed by me. Discussion: http://postgr.es/m/09d8ad33-4287-a09b-a77f-77f8761adb5e@2ndquadrant.com
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Add max_parallel_workers GUC.Robert Haas2016-12-02
| | | | | | | | | | Increase the default value of the existing max_worker_processes GUC from 8 to 16, and add a new max_parallel_workers GUC with a maximum of 8. This way, even if the maximum amount of parallel query is happening, there is still room for background workers that do other things, as originally envisioned when max_worker_processes was added. Julien Rouhaud, reviewed by Amit Kapila and by revised by me.
* Extend framework from commit 53be0b1ad to report latch waits.Robert Haas2016-10-04
| | | | | | | | | | | | | | | | | | | | | | WaitLatch, WaitLatchOrSocket, and WaitEventSetWait now taken an additional wait_event_info parameter; legal values are defined in pgstat.h. This makes it possible to uniquely identify every point in the core code where we are waiting for a latch; extensions can pass WAIT_EXTENSION. Because latches were the major wait primitive not previously covered by this patch, it is now possible to see information in pg_stat_activity on a large number of important wait events not previously addressed, such as ClientRead, ClientWrite, and SyncRep. Unfortunately, many of the wait events added by this patch will fail to appear in pg_stat_activity because they're only used in background processes which don't currently appear in pg_stat_activity. We should fix this either by creating a separate view for such information, or else by deciding to include them in pg_stat_activity after all. Michael Paquier and Robert Haas, reviewed by Alexander Korotkov and Thomas Munro.
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