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path: root/src/backend/access/transam/xlogfuncs.c
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* Make pg_receivexlog and pg_basebackup -X stream work across timeline switches.Heikki Linnakangas2013-01-17
| | | | | | | | | | | | | | | | | | | | | | This mirrors the changes done earlier to the server in standby mode. When receivelog reaches the end of a timeline, as reported by the server, it fetches the timeline history file of the next timeline, and restarts streaming from the new timeline by issuing a new START_STREAMING command. When pg_receivexlog crosses a timeline, it leaves the .partial suffix on the last segment on the old timeline. This helps you to tell apart a partial segment left in the directory because of a timeline switch, and a completed segment. If you just follow a single server, it won't make a difference, but it can be significant in more complicated scenarios where new WAL is still generated on the old timeline. This includes two small changes to the streaming replication protocol: First, when you reach the end of timeline while streaming, the server now sends the TLI of the next timeline in the server's history to the client. pg_receivexlog uses that as the next timeline, so that it doesn't need to parse the timeline history file like a standby server does. Second, when BASE_BACKUP command sends the begin and end WAL positions, it now also sends the timeline IDs corresponding the positions.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Follow TLI of last replayed record, not recovery target TLI, in walsenders.Heikki Linnakangas2012-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most of the time, the last replayed record comes from the recovery target timeline, but there is a corner case where it makes a difference. When the startup process scans for a new timeline, and decides to change recovery target timeline, there is a window where the recovery target TLI has already been bumped, but there are no WAL segments from the new timeline in pg_xlog yet. For example, if we have just replayed up to point 0/30002D8, on timeline 1, there is a WAL file called 000000010000000000000003 in pg_xlog that contains the WAL up to that point. When recovery switches recovery target timeline to 2, a walsender can immediately try to read WAL from 0/30002D8, from timeline 2, so it will try to open WAL file 000000020000000000000003. However, that doesn't exist yet - the startup process hasn't copied that file from the archive yet nor has the walreceiver streamed it yet, so walsender fails with error "requested WAL segment 000000020000000000000003 has already been removed". That's harmless, in that the standby will try to reconnect later and by that time the segment is already created, but error messages that should be ignored are not good. To fix that, have walsender track the TLI of the last replayed record, instead of the recovery target timeline. That way walsender will not try to read anything from timeline 2, until the WAL segment has been created and at least one record has been replayed from it. The recovery target timeline is now xlog.c's internal affair, it doesn't need to be exposed in shared memory anymore. This fixes the error reported by Thom Brown. depesz the same error message, but I'm not sure if this fixes his scenario.
* Allow a streaming replication standby to follow a timeline switch.Heikki Linnakangas2012-12-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch, streaming replication would refuse to start replicating if the timeline in the primary doesn't exactly match the standby. The situation where it doesn't match is when you have a master, and two standbys, and you promote one of the standbys to become new master. Promoting bumps up the timeline ID, and after that bump, the other standby would refuse to continue. There's significantly more timeline related logic in streaming replication now. First of all, when a standby connects to primary, it will ask the primary for any timeline history files that are missing from the standby. The missing files are sent using a new replication command TIMELINE_HISTORY, and stored in standby's pg_xlog directory. Using the timeline history files, the standby can follow the latest timeline present in the primary (recovery_target_timeline='latest'), just as it can follow new timelines appearing in an archive directory. START_REPLICATION now takes a TIMELINE parameter, to specify exactly which timeline to stream WAL from. This allows the standby to request the primary to send over WAL that precedes the promotion. The replication protocol is changed slightly (in a backwards-compatible way although there's little hope of streaming replication working across major versions anyway), to allow replication to stop when the end of timeline reached, putting the walsender back into accepting a replication command. Many thanks to Amit Kapila for testing and reviewing various versions of this patch.
* Make xlog_internal.h includable in frontend context.Heikki Linnakangas2012-12-13
| | | | | | | This makes unnecessary the ugly hack used to #include postgres.h in pg_basebackup. Based on Alvaro Herrera's patch
* Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera2012-08-30
| | | | | | | | | | | | This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
* Replace XLogRecPtr struct with a 64-bit integer.Heikki Linnakangas2012-06-24
| | | | | | | | | | | | | | This simplifies code that needs to do arithmetic on XLogRecPtrs. To avoid changing on-disk format of data pages, the LSN on data pages is still stored in the old format. That should keep pg_upgrade happy. However, we have XLogRecPtrs embedded in the control file, and in the structs that are sent over the replication protocol, so this changes breaks compatibility of pg_basebackup and server. I didn't do anything about this in this patch, per discussion on -hackers, the right thing to do would to be to change the replication protocol to be architecture-independent, so that you could use a newer version of pg_receivexlog, for example, against an older server version.
* Don't waste the last segment of each 4GB logical log file.Heikki Linnakangas2012-06-24
| | | | | | | | | | | | | | | | The comments claimed that wasting the last segment made it easier to do calculations with XLogRecPtrs, because you don't have problems representing last-byte-position-plus-1 that way. In my experience, however, it only made things more complicated, because the there was two ways to represent the boundary at the beginning of a logical log file: logid = n+1 and xrecoff = 0, or as xlogid = n and xrecoff = 4GB - XLOG_SEG_SIZE. Some functions were picky about which representation was used. Also, use a 64-bit segment number instead of the log/seg combination, to point to a certain WAL segment. We assume that all platforms have a working 64-bit integer type nowadays. This is an incompatible change in WAL format, so bumping WAL version number.
* Improve readability and error messages in pg_backup_start_time.Robert Haas2012-06-14
| | | | Gurjeet Singh, with corrections by me.
* New SQL functons pg_backup_in_progress() and pg_backup_start_time()Robert Haas2012-06-14
| | | | | Darold Gilles, reviewed by Gabriele Bartolini and others, rebased by Marco Nenciarini. Stylistic cleanup and OID fixes by me.
* More carefully validate xlog location string inputsMagnus Hagander2012-03-04
| | | | | | | Now that we have validate_xlog_location, call it from the previously existing functions taking xlog locatoins as a string input. Suggested by Fujii Masao
* Add function pg_xlog_location_diff to help comparisonsMagnus Hagander2012-03-04
| | | | | | | | Comparing two xlog locations are useful for example when calculating replication lag. Euler Taveira de Oliveira, reviewed by Fujii Masao, and some cleanups from me
* Remove useless 'needlock' argument from GetXLogInsertRecPtr. It was alwaysHeikki Linnakangas2012-01-11
| | | | passed as 'true'.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Move user functions related to WAL into xlogfuncs.cSimon Riggs2011-11-04