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* Speedup 2PC recovery by skipping two phase state files in normal pathSimon Riggs2017-04-04
| | | | | | | | | | | 2PC state info held in shmem at PREPARE, then cleaned at COMMIT PREPARED/ABORT PREPARED, avoiding writing/fsyncing any state information to disk in the normal path, greatly enhancing replay speed. Prepared transactions that live past one checkpoint redo horizon will be written to disk as now. Similar conceptually to 978b2f65aa1262eb4ecbf8b3785cb1b9cf4db78e and building upon the infrastructure created by that commit. Authors, in equal measure: Stas Kelvich, Nikhil Sontakke and Michael Paquier Discussion: https://postgr.es/m/CAMGcDxf8Bn9ZPBBJZba9wiyQq-Qk5uqq=VjoMnRnW5s+fKST3w@mail.gmail.com
* Correct grammar in error messageSimon Riggs2017-03-28
| | | | | "could not generate" rather than "could not generation" from commit 818fd4a67d610991757b610755e3065fb99d80a5
* Suppress implicit-conversion warnings seen with newer clang versions.Tom Lane2017-03-28
| | | | | | | | | | | | | | | We were assigning values near 255 through "char *" pointers. On machines where char is signed, that's not entirely kosher, and it's reasonable for compilers to warn about it. A better solution would be to change the pointer type to "unsigned char *", but that would be vastly more invasive. For the moment, let's just apply this simple backpatchable solution. Aleksander Alekseev Discussion: https://postgr.es/m/20170220141239.GD12278@e733.localdomain Discussion: https://postgr.es/m/2839.1490714708@sss.pgh.pa.us
* Fsync directory after creating or unlinking file.Teodor Sigaev2017-03-27
| | | | | | | | | If file was created/deleted just before powerloss it's possible that file system will miss that. To prevent it, call fsync() where creating/ unlinkg file is critical. Author: Michael Paquier Reviewed-by: Ashutosh Bapat, Takayuki Tsunakawa, me
* Fix backup cancelingTeodor Sigaev2017-03-24
| | | | | | | | | | | | | | | | | Assert-enabled build crashes but without asserts it works by wrong way: it may not reset forcing full page write and preventing from starting exclusive backup with the same name as cancelled. Patch replaces pair of booleans nonexclusive_backup_running/exclusive_backup_running to single enum to correctly describe backup state. Backpatch to 9.6 where bug was introduced Reported-by: David Steele Authors: Michael Paquier, David Steele Reviewed-by: Anastasia Lubennikova https://commitfest.postgresql.org/13/1068/
* Track the oldest XID that can be safely looked up in CLOG.Robert Haas2017-03-23
| | | | | | | | | | | | | | This provides infrastructure for looking up arbitrary, user-supplied XIDs without a risk of scary-looking failures from within the clog module. Normally, the oldest XID that can be safely looked up in CLOG is the same as the oldest XID that can reused without causing wraparound, and the latter is already tracked. However, while truncation is in progress, the values are different, so we must keep track of them separately. Craig Ringer, reviewed by Simon Riggs and by me. Discussion: http://postgr.es/m/CAMsr+YHQiWNEi0daCTboS40T+V5s_+dst3PYv_8v2wNVH+Xx4g@mail.gmail.com
* Replication lag tracking for walsendersSimon Riggs2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | Adds write_lag, flush_lag and replay_lag cols to pg_stat_replication. Implements a lag tracker module that reports the lag times based upon measurements of the time taken for recent WAL to be written, flushed and replayed and for the sender to hear about it. These times represent the commit lag that was (or would have been) introduced by each synchronous commit level, if the remote server was configured as a synchronous standby. For an asynchronous standby, the replay_lag column approximates the delay before recent transactions became visible to queries. If the standby server has entirely caught up with the sending server and there is no more WAL activity, the most recently measured lag times will continue to be displayed for a short time and then show NULL. Physical replication lag tracking is automatic. Logical replication tracking is possible but is the responsibility of the logical decoding plugin. Tracking is a private module operating within each walsender individually, with values reported to shared memory. Module not used outside of walsender. Design and code is good enough now to commit - kudos to the author. In many ways a difficult topic, with important and subtle behaviour so this shoudl be expected to generate discussion and multiple open items: Test now! Author: Thomas Munro, following designs by Fujii Masao and Simon Riggs Review: Simon Riggs, Ian Barwick and Craig Ringer
* Expose waitforarchive option through pg_stop_backup()Stephen Frost2017-03-22
| | | | | | | | | | | | | | | | | Internally, we have supported the option to either wait for all of the WAL associated with a backup to be archived, or to return immediately. This option is useful to users of pg_stop_backup() as well, when they are reading the stop backup record position and checking that the WAL they need has been archived independently. This patch adds an additional, optional, argument to pg_stop_backup() which allows the user to indicate if they wish to wait for the WAL to be archived or not. The default matches current behavior, which is to wait. Author: David Steele, with some minor changes, doc updates by me. Reviewed by: Takayuki Tsunakawa, Fujii Masao Discussion: https://postgr.es/m/758e3fd1-45b4-5e28-75cd-e9e7f93a4c02@pgmasters.net
* Refactor GetOldestXmin() to use flagsSimon Riggs2017-03-22
| | | | | | | Replace ignoreVacuum parameter with more flexible flags. Author: Eiji Seki Review: Haribabu Kommi
* Create and use wait events for read, write, and fsync operations.Robert Haas2017-03-18
| | | | | | | | | | | | | Previous commits, notably 53be0b1add7064ca5db3cd884302dfc3268d884e and 6f3bd98ebfc008cbd676da777bb0b2376c4c4bfa, made it possible to see from pg_stat_activity when a backend was stuck waiting for another backend, but it's also fairly common for a backend to be stuck waiting for an I/O. Add wait events for those operations, too. Rushabh Lathia, with further hacking by me. Reviewed and tested by Michael Paquier, Amit Kapila, Rajkumar Raghuwanshi, and Rahila Syed. Discussion: http://postgr.es/m/CAGPqQf0LsYHXREPAZqYGVkDqHSyjf=KsD=k0GTVPAuzyThh-VQ@mail.gmail.com
* Rename "pg_clog" directory to "pg_xact".Robert Haas2017-03-17
| | | | | | | | | | | Names containing the letters "log" sometimes confuse users into believing that only non-critical data is present. It is hoped this renaming will discourage ill-considered removals of transaction status data. Michael Paquier Discussion: http://postgr.es/m/CA+Tgmoa9xFQyjRZupbdEFuwUerFTvC6HjZq1ud6GYragGDFFgA@mail.gmail.com
* Spelling fixesPeter Eisentraut2017-03-14
| | | | From: Josh Soref <jsoref@gmail.com>
* Make logging about multixact wraparound protection less chatty.Tom Lane2017-03-14
| | | | | | | | | | | | | | The original messaging design, introduced in commit 068cfadf9, seems too chatty now that some time has elapsed since the bug fix; most installations will be in good shape and don't really need a reminder about this on every postmaster start. Hence, arrange to suppress the "wraparound protections are now enabled" message during startup (specifically, during the TrimMultiXact() call). The message will still appear if protection becomes effective at some later point. Discussion: https://postgr.es/m/17211.1489189214@sss.pgh.pa.us
* Change xlog to WAL in some error messagesPeter Eisentraut2017-03-13
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* Support SCRAM-SHA-256 authentication (RFC 5802 and 7677).Heikki Linnakangas2017-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces a new generic SASL authentication method, similar to the GSS and SSPI methods. The server first tells the client which SASL authentication mechanism to use, and then the mechanism-specific SASL messages are exchanged in AuthenticationSASLcontinue and PasswordMessage messages. Only SCRAM-SHA-256 is supported at the moment, but this allows adding more SASL mechanisms in the future, without changing the overall protocol. Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later. The SASLPrep algorithm, for pre-processing the password, is not yet implemented. That could cause trouble, if you use a password with non-ASCII characters, and a client library that does implement SASLprep. That will hopefully be added later. Authorization identities, as specified in the SCRAM-SHA-256 specification, are ignored. SET SESSION AUTHORIZATION provides more or less the same functionality, anyway. If a user doesn't exist, perform a "mock" authentication, by constructing an authentic-looking challenge on the fly. The challenge is derived from a new system-wide random value, "mock authentication nonce", which is created at initdb, and stored in the control file. We go through these motions, in order to not give away the information on whether the user exists, to unauthenticated users. Bumps PG_CONTROL_VERSION, because of the new field in control file. Patch by Michael Paquier and Heikki Linnakangas, reviewed at different stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev, and many others. Discussion: https://www.postgresql.org/message-id/CAB7nPqRbR3GmFYdedCAhzukfKrgBLTLtMvENOmPrVWREsZkF8g%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/CAB7nPqSMXU35g%3DW9X74HVeQp0uvgJxvYOuA4A-A3M%2B0wfEBv-w%40mail.gmail.com Discussion: https://www.postgresql.org/message-id/55192AFE.6080106@iki.fi
* Fix incorrect variable datatypeMagnus Hagander2017-02-28
| | | | | | | Both datatypes map to the same underlying one which is why it still worked, but we should use the correct type. Author: Kyotaro HORIGUCHI
* Consistently declare timestamp variables as TimestampTz.Tom Lane2017-02-23
| | | | | | | | | | | | | | | | | | | Twiddle the replication-related code so that its timestamp variables are declared TimestampTz, rather than the uninformative "int64" that was previously used for meant-to-be-always-integer timestamps. This resolves the int64-vs-TimestampTz declaration inconsistencies introduced by commit 7c030783a, though in the opposite direction to what was originally suggested. This required including datatype/timestamp.h in a couple more places than before. I decided it would be a good idea to slim down that header by not having it pull in <float.h> etc, as those headers are no longer at all relevant to its purpose. Unsurprisingly, a small number of .c files turn out to have been depending on those inclusions, so add them back in the .c files as needed. Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us Discussion: https://postgr.es/m/27694.1487456324@sss.pgh.pa.us
* Remove pg_control's enableIntTimes field.Tom Lane2017-02-23
| | | | | | | | | | | | | | | We don't need it any more. pg_controldata continues to report that date/time type storage is "64-bit integers", but that's now a hard-wired behavior not something it sees in the data. This avoids breaking pg_upgrade, and perhaps other utilities that inspect pg_control this way. Ditto for pg_resetwal. I chose to remove the "bigint_timestamps" output column of pg_control_init(), though, as that function hasn't been around long and probably doesn't have ossified users. Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
* Minor fixes for WAL consistency checking.Robert Haas2017-02-14
| | | | | | Michael Paquier, reviewed and slightly revised by me. Discussion: http://postgr.es/m/CAB7nPqRzCQb=vdfHvMtP0HMLBHU6z1aGdo4GJsUP-HP8jx+Pkw@mail.gmail.com
* Rename dtrace probes for ongoing xlog -> wal conversion.Robert Haas2017-02-09
| | | | xlog-switch becomes wal-switch, and xlog-insert becomes wal-insert.
* Remove all references to "xlog" from SQL-callable functions in pg_proc.Robert Haas2017-02-09
| | | | | | | | | | | | | | Commit f82ec32ac30ae7e3ec7c84067192535b2ff8ec0e renamed the pg_xlog directory to pg_wal. To make things consistent, and because "xlog" is terrible terminology for either "transaction log" or "write-ahead log" rename all SQL-callable functions that contain "xlog" in the name to instead contain "wal". (Note that this may pose an upgrade hazard for some users.) Similarly, rename the xlog_position argument of the functions that create slots to be called wal_position. Discussion: https://www.postgresql.org/message-id/CA+Tgmob=YmA=H3DbW1YuOXnFVgBheRmyDkWcD9M8f=5bGWYEoQ@mail.gmail.com
* Add WAL consistency checking facility.Robert Haas2017-02-08
| | | | | | | | | | | | | | When the new GUC wal_consistency_checking is set to a non-empty value, it triggers recording of additional full-page images, which are compared on the standby against the results of applying the WAL record (without regard to those full-page images). Allowable differences such as hints are masked out, and the resulting pages are compared; any difference results in a FATAL error on the standby. Kuntal Ghosh, based on earlier patches by Michael Paquier and Heikki Linnakangas. Extensively reviewed and revised by Michael Paquier and by me, with additional reviews and comments from Amit Kapila, Álvaro Herrera, Simon Riggs, and Peter Eisentraut.
* Fix an assertion failure related to an exclusive backup.Fujii Masao2017-01-17
| | | | | | | | | | | | | | | | | | | | | | Previously multiple sessions could execute pg_start_backup() and pg_stop_backup() to start and stop an exclusive backup at the same time. This could trigger the assertion failure of "FailedAssertion("!(XLogCtl->Insert.exclusiveBackup)". This happend because, even while pg_start_backup() was starting an exclusive backup, other session could run pg_stop_backup() concurrently and mark the backup as not-in-progress unconditionally. This patch introduces ExclusiveBackupState indicating the state of an exclusive backup. This state is used to ensure that there is only one session running pg_start_backup() or pg_stop_backup() at the same time, to avoid the assertion failure. Back-patch to all supported versions. Author: Michael Paquier Reviewed-By: Kyotaro Horiguchi and me Reported-By: Andreas Seltenreich Discussion: <87mvktojme.fsf@credativ.de>
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Skip checkpoints, archiving on idle systems.Andres Freund2016-12-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some background activity (like checkpoints, archive timeout, standby snapshots) is not supposed to happen on an idle system. Unfortunately so far it was not easy to determine when a system is idle, which defeated some of the attempts to avoid redundant activity on an idle system. To make that easier, allow to make individual WAL insertions as not being "important". By checking whether any important activity happened since the last time an activity was performed, it now is easy to check whether some action needs to be repeated. Use the new facility for checkpoints, archive timeout and standby snapshots. The lack of a facility causes some issues in older releases, but in my opinion the consequences (superflous checkpoints / archived segments) aren't grave enough to warrant backpatching. Author: Michael Paquier, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Amit Kapila, Kyotaro HORIGUCHI Bug: #13685 Discussion: https://www.postgresql.org/message-id/20151016203031.3019.72930@wrigleys.postgresql.org https://www.postgresql.org/message-id/CAB7nPqQcPqxEM3S735Bd2RzApNqSNJVietAC=6kfkYv_45dKwA@mail.gmail.com Backpatch: -
* Simplify LWLock tranche machinery by removing array_base/array_stride.Robert Haas2016-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | array_base and array_stride were added so that we could identify the offset of an LWLock within a tranche, but this facility is only very marginally used apart from the main tranche. So, give every lock in the main tranche its own tranche ID and get rid of array_base, array_stride, and all that's attached. For debugging facilities (Trace_lwlocks and LWLOCK_STATS) print the pointer address of the LWLock using %p instead of the offset. This is arguably more useful, and certainly a lot cheaper. Drop the offset-within-tranche from the information reported to dtrace and from one can't-happen message inside lwlock.c. The main user-visible impact of this change is that pg_stat_activity will now report all waits for LWLocks as "LWLock" rather than reporting some as "LWLockTranche" and others as "LWLockNamed". The main motivation for this change is that the need to specify an array_base and an array_stride is awkward for parallel query. There is only a very limited supply of tranche IDs so we can't just keep allocating new ones, and if we try to use the same tranche IDs every time then we run into trouble when multiple parallel contexts are use simultaneously. So if we didn't get rid of this mechanism we'd have to make it even more complicated. By simplifying it in this way, we instead reduce the size of the generated code for lwlock.c by about 5%. Discussion: http://postgr.es/m/CA+TgmoYsFn6NUW1x0AZtupJGUAs1UDY4dJtCN47_Q6D0sP80PA@mail.gmail.com
* Bring some clarity to the defaults for the xxx_flush_after parameters.Tom Lane2016-11-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Instead of confusingly stating platform-dependent defaults for these parameters in the comments in postgresql.conf.sample (with the main entry being a lie on Linux), teach initdb to install the correct platform-dependent value in postgresql.conf, similarly to the way we handle other platform-dependent defaults. This won't do anything for existing 9.6 installations, but since it's effectively only a documentation improvement, that seems OK. Since this requires initdb to have access to the default values, move the #define's for those to pg_config_manual.h; the original placement in bufmgr.h is unworkable because that file can't be included by frontend programs. Adjust the default value for wal_writer_flush_after so that it is 1MB regardless of XLOG_BLCKSZ, conforming to what is stated in both the SGML docs and postgresql.conf. (We could alternatively make it scale with XLOG_BLCKSZ, but I'm not sure I see the point.) Copy-edit related SGML documentation. Fabien Coelho and Tom Lane, per a gripe from Tomas Vondra. Discussion: <30ebc6e3-8358-09cf-44a8-578252938424@2ndquadrant.com>
* Remove barrier.hRobert Haas2016-11-22
| | | | | | | | A new thing also called a "barrier" is proposed, but whether we decide to take that patch or not, this file seems to have outlived its usefulness. Thomas Munro
* Fix silly nil-pointer-dereference bug introduced in commit d5f6f13f8.Tom Lane2016-11-06
| | | | | | | Don't fetch record->xl_info before we've verified that record isn't NULL. Per Coverity. Michael Paquier
* Be more consistent about masking xl_info with ~XLR_INFO_MASK.Tom Lane2016-11-04
| | | | | | | | | | | | Generally, WAL resource managers are only supposed to examine the top 4 bits of a WAL record's xl_info; the rest are reserved for the WAL mechanism itself. A few places were not consistent about doing this with respect to XLOG_CHECKPOINT and XLOG_SWITCH records. There's no bug currently, since no additional bits ever get set in these specific record types, but that might not be true forever. Let's follow the generic coding rule here too. Michael Paquier
* Fix leftover reference to background writer performing checkpoints.Robert Haas2016-10-28
| | | | | This was changed in PostgreSQL 9.2, but somehow this comment never got updated.
* Fix possible pg_basebackup failure on standby with "include WAL".Robert Haas2016-10-27
| | | | | | | | | | | | | | | If a restartpoint flushed no dirty buffers, it could fail to update the minimum recovery point, leading to a minimum recovery point prior to the starting REDO location. perform_base_backup() would interpret that as meaning that no WAL files at all needed to be included in the backup, failing an internal sanity check. To fix, have restartpoints always update the minimum recovery point to just after the checkpoint record itself, so that the file (or files) containing the checkpoint record will always be included in the backup. Code by Amit Kapila, per a design suggestion by me, with some additional work on the code comment by me. Test case by Michael Paquier. Report by Kyotaro Horiguchi.
* Fix comment formatting.Robert Haas2016-10-21
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* Rename "pg_xlog" directory to "pg_wal".Robert Haas2016-10-20
| | | | | | | | | | | | | | | | | | | | | "xlog" is not a particularly clear abbreviation for "write-ahead log", and it sometimes confuses users into believe that the contents of the "pg_xlog" directory are not critical data, leading to unpleasant consequences. So, rename the directory to "pg_wal". This patch modifies pg_upgrade and pg_basebackup to understand both the old and new directory layouts; the former is necessary given the purpose of the tool, while the latter merely avoids an unnecessary backward-compatibility break. We may wish to consider renaming other programs, switches, and functions which still use the old "xlog" naming to also refer to "wal". However, that's still under discussion, so let's do just this much for now. Discussion: CAB7nPqTeC-8+zux8_-4ZD46V7YPwooeFxgndfsq5Rg8ibLVm1A@mail.gmail.com Michael Paquier
* 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.
* Delay updating control file to "in production"Peter Eisentraut2016-09-21
| | | | | | | | | | Move the updating of the control file to "in production" status until the point where WAL writes are allowed. Before, there could be a significant gap between the control file update and write transactions actually being allowed. This makes it more reliable to use the control status to verify the end of a promotion. From: Michael Paquier <michael.paquier@gmail.com>
* New recovery target recovery_target_lsnSimon Riggs2016-09-03
| | | | Michael Paquier
* Prevent starting a standalone backend with standby_mode on.Tom Lane2016-08-31
| | | | | | | | | | | | | | | | | | | This can't really work because standby_mode expects there to be more WAL arriving, which there will not ever be because there's no WAL receiver process to fetch it. Moreover, if standby_mode is on then hot standby might also be turned on, causing even more strangeness because that expects read-only sessions to be executing in parallel. Bernd Helmle reported a case where btree_xlog_delete_get_latestRemovedXid got confused, but rather than band-aiding individual problems it seems best to prevent getting anywhere near this state in the first place. Back-patch to all supported branches. In passing, also fix some omissions of errcodes in other ereport's in readRecoveryCommandFile(). Michael Paquier (errcode hacking by me) Discussion: <00F0B2CEF6D0CEF8A90119D4@eje.credativ.lan>
* Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane2016-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
* Remove unused structure member.Robert Haas2016-07-21
| | | | Michael Paquier
* Fix start WAL filename for concurrent backups from standbyMagnus Hagander2016-07-11
| | | | | | | | | | On a standby, ThisTimelineID is always 0, so we would generate a filename in timeline 0 even for other timelines. Instead, use starttli which we have retreived from the controlfile. Report by: Francesco Canovai in bug #14230 Author: Marco Nenciarini Reviewed by: Michael Paquier and Amit Kapila
* pgindent run for 9.6Robert Haas2016-06-09
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* Fix poorly-worded log message.Tom Lane2016-05-08
| | | | Euler Taveira
* Implement backup API functions for non-exclusive backupsMagnus Hagander2016-04-05
| | | | | | | | | | | | | | | | | | | | | Previously non-exclusive backups had to be done using the replication protocol and pg_basebackup. With this commit it's now possible to make them using pg_start_backup/pg_stop_backup as well, as long as the backup program can maintain a persistent connection to the database. Doing this, backup_label and tablespace_map are returned as results from pg_stop_backup() instead of being written to the data directory. This makes the server safe from a crash during an ongoing backup, which can be a problem with exclusive backups. The old syntax of the functions remain and work exactly as before, but since the new syntax is safer this should eventually be deprecated and removed. Only reference documentation is included. The main section on backup still needs to be rewritten to cover this, but since that is already scheduled for a separate large rewrite, it's not included in this patch. Reviewed by David Steele and Amit Kapila
* Display WAL pointer in rm_redo error callbackAlvaro Herrera2016-04-04
| | | | | This makes it easier to identify the source of a recovery problem in case of a bug or data corruption.
* Add new replication mode synchronous_commit = 'remote_apply'.Robert Haas2016-03-29
| | | | | | | | | | | | | | | | | | | In this mode, the master waits for the transaction to be applied on the remote side, not just written to disk. That means that you can count on a transaction started on the standby to see all commits previously acknowledged by the master. To make this work, the standby sends a reply after replaying each commit record generated with synchronous_commit >= 'remote_apply'. This introduces a small inefficiency: the extra replies will be sent even by standbys that aren't the current synchronous standby. But previously-existing synchronous_commit levels make no attempt at all to optimize which replies are sent based on what the primary cares about, so this is no worse, and at least avoids any extra replies for people not using the feature at all. Thomas Munro, reviewed by Michael Paquier and by me. Some additional tweaks by me.
* Merge wal_level "archive" and "hot_standby" into new name "replica"Peter Eisentraut2016-03-18
| | | | | | | | | | | | | | | | | The distinction between "archive" and "hot_standby" existed only because at the time "hot_standby" was added, there was some uncertainty about stability. This is now a long time ago. We would like to move forward with simplifying the replication configuration, but this distinction is in the way, because a primary server cannot tell (without asking a standby or predicting the future) which one of these would be the appropriate level. Pick a new name for the combined setting to make it clearer that it covers all (non-logical) backup and replication uses. The old values are still accepted but are converted internally. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: David Steele <david@pgmasters.net>
* Fix typos in commentsAlvaro Herrera2016-03-15
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* Avoid unlikely data-loss scenarios due to rename() without fsync.Andres Freund2016-03-09
| | | | | | | | | | | | | | | | | | | | | Renaming a file using rename(2) is not guaranteed to be durable in face of crashes. Use the previously added durable_rename()/durable_link_or_rename() in various places where we previously just renamed files. Most of the changed call sites are arguably not critical, but it seems better to err on the side of too much durability. The most prominent known case where the previously missing fsyncs could cause data loss is crashes at the end of a checkpoint. After the actual checkpoint has been performed, old WAL files are recycled. When they're filled, their contents are fdatasynced, but we did not fsync the containing directory. An OS/hardware crash in an unfortunate moment could then end up leaving that file with its old name, but new content; WAL replay would thus not replay it. Reported-By: Tomas Vondra Author: Michael Paquier, Tomas Vondra, Andres Freund Discussion: 56583BDD.9060302@2ndquadrant.com Backpatch: All supported branches
* Ignore recovery_min_apply_delay until recovery has reached consistent stateFujii Masao2016-03-06
| | | | | | | | | | | | | | | | | | | Previously recovery_min_apply_delay was applied even before recovery had reached consistency. This could cause us to wait a long time unexpectedly for read-only connections to be allowed. It's problematic because the standby was useless during that wait time. This patch changes recovery_min_apply_delay so that it's applied once the database has reached the consistent state. That is, even if the delay is set, the standby tries to replay WAL records as fast as possible until it has reached consistency. Author: Michael Paquier Reviewed-By: Julien Rouhaud Reported-By: Greg Clough Backpatch: 9.4, where recovery_min_apply_delay was added Bug: #13770 Discussion: http://www.postgresql.org/message-id/20151111155006.2644.84564@wrigleys.postgresql.org