aboutsummaryrefslogtreecommitdiff
path: root/src/backend/replication/logical/reorderbuffer.c
Commit message (Collapse)AuthorAge
...
* Clean up newlines following left parenthesesAlvaro Herrera2022-05-13
| | | | Like commit c9d297751959.
* Pre-beta mechanical code beautification.Tom Lane2022-05-12
| | | | | Run pgindent, pgperltidy, and reformat-dat-files. I manually fixed a couple of comments that pgindent uglified.
* Fix various typos and spelling mistakes in code commentsDavid Rowley2022-04-11
| | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com
* Revert "Logical decoding of sequences"Tomas Vondra2022-04-07
| | | | | | | | | | | | | | | | | | | | | This reverts a sequence of commits, implementing features related to logical decoding and replication of sequences: - 0da92dc530c9251735fc70b20cd004d9630a1266 - 80901b32913ffa59bf157a4d88284b2b3a7511d9 - b779d7d8fdae088d70da5ed9fcd8205035676df3 - d5ed9da41d96988d905b49bebb273a9b2d6e2915 - a180c2b34de0989269fdb819bff241a249bf5380 - 75b1521dae1ff1fde17fda2e30e591f2e5d64b6a - 2d2232933b02d9396113662e44dca5f120d6830e - 002c9dd97a0c874fd1693a570383e2dd38cd40d5 - 05843b1aa49df2ecc9b97c693b755bd1b6f856a9 The implementation has issues, mostly due to combining transactional and non-transactional behavior of sequences. It's not clear how this could be fixed, but it'll require reworking significant part of the patch. Discussion: https://postgr.es/m/95345a19-d508-63d1-860a-f5c2f41e8d40@enterprisedb.com
* Improve the generation memory allocatorDavid Rowley2022-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Here we make a series of improvements to the generation memory allocator, namely: 1. Allow generation contexts to have a minimum, initial and maximum block sizes. The standard allocator allows this already but when the generation context was added, it only allowed fixed-sized blocks. The problem with fixed-sized blocks is that it's difficult to choose how large to make the blocks. If the chosen size is too small then we'd end up with a large number of blocks and a large number of malloc calls. If the block size is made too large, then memory is wasted. 2. Add support for "keeper" blocks. This is a special block that is allocated along with the context itself but is never freed. Instead, when the last chunk in the keeper block is freed, we simply mark the block as empty to allow new allocations to make use of it. 3. Add facility to "recycle" newly empty blocks instead of freeing them and having to later malloc an entire new block again. We do this by recording a single GenerationBlock which has become empty of any chunks. When we run out of space in the current block, we check to see if there is a "freeblock" and use that if it contains enough space for the allocation. Author: David Rowley, Tomas Vondra Reviewed-by: Andy Fan Discussion: https://postgr.es/m/d987fd54-01f8-0f73-af6c-519f799a0ab8@enterprisedb.com
* Logical decoding of sequencesTomas Vondra2022-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This extends the logical decoding to also decode sequence increments. We differentiate between sequences created in the current (in-progress) transaction, and sequences created earlier. This mixed behavior is necessary because while sequences are not transactional (increments are not subject to ROLLBACK), relfilenode changes are. So we do this: * Changes for sequences created in the same top-level transaction are treated as transactional, i.e. just like any other change from that transaction, and discarded in case of a rollback. * Changes for sequences created earlier are applied immediately, as if performed outside any transaction. This applies also after ALTER SEQUENCE, which may create a new relfilenode. Moreover, if we ever get support for DDL replication, the sequence won't exist until the transaction gets applied. Sequences created in the current transaction are tracked in a simple hash table, identified by a relfilenode. That means a sequence may already exist, but if a transaction does ALTER SEQUENCE then the increments for the new relfilenode will be treated as transactional. For each relfilenode we track the XID of (sub)transaction that created it, which is needed for cleanup at transaction end. We don't need to check the XID to decide if an increment is transactional - if we find a match in the hash table, it has to be the same transaction. This requires two minor changes to WAL-logging. Firstly, we need to ensure the sequence record has a valid XID - until now the the increment might have XID 0 if it was the first change in a subxact. But the sequence might have been created in the same top-level transaction. So we ensure the XID is assigned when WAL-logging increments. The other change is addition of "created" flag, marking increments for newly created relfilenodes. This makes it easier to maintain the hash table of sequences that need transactional handling. Note: This is needed because of subxacts. A XID 0 might still have the sequence created in a different subxact of the same top-level xact. This does not include any changes to test_decoding and/or the built-in replication - those will be committed in separate patches. A patch adding decoding of sequences was originally submitted by Cary Huang. This commit reworks various important aspects (e.g. the WAL logging and transactional/non-transactional handling). However, the original patch and reviews were very useful. Author: Tomas Vondra, Cary Huang Reviewed-by: Peter Eisentraut, Hannu Krosing, Andres Freund Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca
* Fix various typos, grammar and code style in comments and docsMichael Paquier2022-01-25
| | | | | | | | | This fixes a set of issues that have accumulated over the past months (or years) in various code areas. Most fixes are related to some recent additions, as of the development of v15. Author: Justin Pryzby Discussion: https://postgr.es/m/20220124030001.GQ23027@telsasoft.com
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Fix some typos with {a,an}Michael Paquier2021-12-09
| | | | | | | | One of the changes impacts the documentation, so backpatch. Author: Peter Smith Discussion: https://postgr.es/m/CAHut+Pu6+c+r3mY24VT7u+H+E_s6vMr5OdRiZ8NT3EOa-E5Lmw@mail.gmail.com Backpatch-through: 14
* Add parent table name in an error in reorderbuffer.c.Amit Kapila2021-09-22
| | | | | | | | | This can help in troubleshooting the cause of a particular error that can occur during decoding. Author: Jeremy Schneider Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/808ed65b-994c-915a-361c-577f088b837f@amazon.com
* Fix reorder buffer memory accounting for toast changes.Amit Kapila2021-09-13
| | | | | | | | | | | | | | | | | While processing toast changes in logical decoding, we rejigger the tuple change to point to in-memory toast tuples instead to on-disk toast tuples. And, to make sure the memory accounting is correct, we were subtracting the old change size and then after re-computing the new tuple, re-adding its size at the end. Now, if there is any error before we add the new size, we will release the changes and that will update the accounting info (subtracting the size from the counters). And we were underflowing there which leads to an assertion failure in assert enabled builds and wrong memory accounting in reorder buffer otherwise. Author: Bertrand Drouvot Reviewed-by: Amit Kapila Backpatch-through: 13, where memory accounting was introduced Discussion: https://postgr.es/m/92b0ee65-b8bd-e42d-c082-4f3f4bf12d34@amazon.com
* Add support for prepared transactions to built-in logical replication.Amit Kapila2021-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To add support for streaming transactions at prepare time into the built-in logical replication, we need to do the following things: * Modify the output plugin (pgoutput) to implement the new two-phase API callbacks, by leveraging the extended replication protocol. * Modify the replication apply worker, to properly handle two-phase transactions by replaying them on prepare. * Add a new SUBSCRIPTION option "two_phase" to allow users to enable two-phase transactions. We enable the two_phase once the initial data sync is over. We however must explicitly disable replication of two-phase transactions during replication slot creation, even if the plugin supports it. We don't need to replicate the changes accumulated during this phase, and moreover, we don't have a replication connection open so we don't know where to send the data anyway. The streaming option is not allowed with this new two_phase option. This can be done as a separate patch. We don't allow to toggle two_phase option of a subscription because it can lead to an inconsistent replica. For the same reason, we don't allow to refresh the publication once the two_phase is enabled for a subscription unless copy_data option is false. Author: Peter Smith, Ajin Cherian and Amit Kapila based on previous work by Nikhil Sontakke and Stas Kelvich Reviewed-by: Amit Kapila, Sawada Masahiko, Vignesh C, Dilip Kumar, Takamichi Osumi, Greg Nancarrow Tested-By: Haiying Tang Discussion: https://postgr.es/m/02DA5F5E-CECE-4D9C-8B4B-418077E2C010@postgrespro.ru Discussion: https://postgr.es/m/CAA4eK1+opiV4aFTmWWUF9h_32=HfPOW9vZASHarT0UA5oBrtGw@mail.gmail.com
* Fix typos in pgstat.c, reorderbuffer.c and pathnodes.hDaniel Gustafsson2021-07-08
| | | | | | Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/50250765-5B87-4AD7-9770-7FCED42A6175@yesql.se
* Allow streaming the changes after speculative aborts.Amit Kapila2021-06-30
| | | | | | | | | | | | | | | | | | Until now, we didn't allow to stream the changes in logical replication till we receive speculative confirm or the next DML change record after speculative inserts. The reason was that we never use to process speculative aborts but after commit 4daa140a2f it is possible to process them so we can allow streaming once we receive speculative abort after speculative insertion. We decided to backpatch to 14 where the feature for streaming in progress transactions have been introduced as this is a minor change and makes that functionality better. Author: Amit Kapila Reviewed-By: Dilip Kumar Backpatch-through: 14 Discussion: https://postgr.es/m/CAA4eK1KdqmTCtrBR6oFfGELrLLbDLDedL6zACcsUOQuTJBj1vw@mail.gmail.com
* Pre branch pgindent / pgperltidy runAndrew Dunstan2021-06-28
| | | | | Along the way make a slight adjustment to src/include/utils/queryjumble.h to avoid an unused typedef.
* Fix decoding of speculative aborts.Amit Kapila2021-06-15
| | | | | | | | | | | | | | | | | | | | | | During decoding for speculative inserts, we were relying for cleaning toast hash on confirmation records or next change records. But that could lead to multiple problems (a) memory leak if there is neither a confirmation record nor any other record after toast insertion for a speculative insert in the transaction, (b) error and assertion failures if the next operation is not an insert/update on the same table. The fix is to start queuing spec abort change and clean up toast hash and change record during its processing. Currently, we are queuing the spec aborts for both toast and main table even though we perform cleanup while processing the main table's spec abort record. Later, if we have a way to distinguish between the spec abort record of toast and the main table, we can avoid queuing the change for spec aborts of toast tables. Reported-by: Ashutosh Bapat Author: Dilip Kumar Reviewed-by: Amit Kapila Backpatch-through: 9.6, where it was introduced Discussion: https://postgr.es/m/CAExHW5sPKF-Oovx_qZe4p5oM6Dvof7_P+XgsNAViug15Fm99jA@mail.gmail.com
* Don't use Asserts to check for violations of replication protocol.Tom Lane2021-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | Using an Assert to check the validity of incoming messages is an extremely poor decision. In a debug build, it should not be that easy for a broken or malicious remote client to crash the logrep worker. The consequences could be even worse in non-debug builds, which will fail to make such checks at all, leading to who-knows-what misbehavior. Hence, promote every Assert that could possibly be triggered by wrong or out-of-order replication messages to a full test-and-ereport. To avoid bloating the set of messages the translation team has to cope with, establish a policy that replication protocol violation error reports don't need to be translated. Hence, all the new messages here use errmsg_internal(). A couple of old messages are changed likewise for consistency. Along the way, fix some non-idiomatic or outright wrong uses of hash_search(). Most of these mistakes are new with the "streaming replication" patch (commit 464824323), but a couple go back a long way. Back-patch as appropriate. Discussion: https://postgr.es/m/1719083.1623351052@sss.pgh.pa.us
* Fix assertion during streaming of multi-insert toast changes.Amit Kapila2021-05-27
| | | | | | | | | | | | | | | | | | | | While decoding the multi-insert WAL we can't clean the toast untill we get the last insert of that WAL record. Now if we stream the changes before we get the last change, the memory for toast chunks won't be released and we expect the txn to have streamed all changes after streaming. This restriction is mainly to ensure the correctness of streamed transactions and it doesn't seem worth uplifting such a restriction just to allow this case because anyway we will stream the transaction once such an insert is complete. Previously we were using two different flags (one for toast tuples and another for speculative inserts) to indicate partial changes. Now instead we replaced both of them with a single flag to indicate partial changes. Reported-by: Pavan Deolasee Author: Dilip Kumar Reviewed-by: Pavan Deolasee, Amit Kapila Discussion: https://postgr.es/m/CABOikdN-_858zojYN-2tNcHiVTw-nhxPwoQS4quExeweQfG1Ug@mail.gmail.com
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
* Update replication statistics after every stream/spill.Amit Kapila2021-05-06
| | | | | | | | | | | | | | Currently, replication slot statistics are updated at prepare, commit, and rollback. Now, if the transaction is interrupted the stats might not get updated. Fixed this by updating replication statistics after every stream/spill. In passing update the docs to change the description of some of the slot stats. Author: Vignesh C, Sawada Masahiko Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Tighten the concurrent abort check during decoding.Amit Kapila2021-05-06
| | | | | | | | | | | | During decoding of an in-progress or prepared transaction, we detect concurrent abort with an error code ERRCODE_TRANSACTION_ROLLBACK. That is not sufficient because a callback can decide to throw that error code at other times as well. Reported-by: Tom Lane Author: Amit Kapila Reviewed-by: Dilip Kumar Discussion: https://postgr.es/m/CAA4eK1KCjPRS4aZHB48QMM4J8XOC1+TD8jo-4Yu84E+MjwqVhA@mail.gmail.com
* Fix the computation of slot stats for 'total_bytes'.Amit Kapila2021-05-03
| | | | | | | | | | | | Previously, we were using the size of all the changes present in ReorderBuffer to compute total_bytes after decoding a transaction and that can lead to counting some of the transactions' changes more than once. Fix it by using the size of the changes decoded for a transaction to compute 'total_bytes'. Author: Sawada Masahiko Reviewed-by: Vignesh C, Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Fix the bugs in selecting the transaction for streaming.Amit Kapila2021-04-30
| | | | | | | | | | | | | | | | There were two problems: a. We were always selecting the next available txn instead of selecting it when it is larger than the previous transaction. b. We were selecting the transactions which haven't made any changes to the database (base snapshot is not set). Later it was hitting an Assert because we don't decode such transactions and the changes in txn remain as it is. It is better not to choose such transactions for streaming in the first place. Reported-by: Haiying Tang Author: Dilip Kumar Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/OS0PR01MB61133B94E63177040F7ECDA1FB429@OS0PR01MB6113.jpnprd01.prod.outlook.com
* Avoid sending prepare multiple times while decoding.Amit Kapila2021-04-26
| | | | | | | | | | | | We send the prepare for the concurrently aborted xacts so that later when rollback prepared is decoded and sent, the downstream should be able to rollback such a xact. For 'streaming' case (when we send changes for in-progress transactions), we were sending prepare twice when concurrent abort was detected. Author: Peter Smith Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/f82133c6-6055-b400-7922-97dae9f2b50b@enterprisedb.com
* Fix typo in reorderbuffer.c.Amit Kapila2021-04-26
| | | | | Author: Peter Smith Discussion: https://postgr.es/m/CAHut+PtvzuYY0zu=dVRK_WVz5WGos1+otZWgEWqjha1ncoSRag@mail.gmail.com
* Add information of total data processed to replication slot stats.Amit Kapila2021-04-16
| | | | | | | | | | | | This adds the statistics about total transactions count and total transaction data logically sent to the decoding output plugin from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats. Suggested-by: Andres Freund Author: Vignesh C and Amit Kapila Reviewed-by: Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Ensure to send a prepare after we detect concurrent abort during decoding.Amit Kapila2021-04-01
| | | | | | | | | | | | | It is possible that while decoding a prepared transaction, it gets aborted concurrently via a ROLLBACK PREPARED command. In that case, we were skipping all the changes and directly sending Rollback Prepared when we find the same in WAL. However, the downstream has no idea of the GID of such a transaction. So, ensure to send prepare even when a concurrent abort is detected. Author: Ajin Cherian Reviewed-by: Markus Wanner, Amit Kapila Discussion: https://postgr.es/m/f82133c6-6055-b400-7922-97dae9f2b50b@enterprisedb.com
* Sanitize the term "combo CID" in code commentsMichael Paquier2021-03-25
| | | | | | | | | Combo CIDs were referred in the code comments using different terms across various places of the code, so unify a bit the term used with what is currently in use in some of the READMEs. Author: "Hou, Zhijie" Discussion: https://postgr.es/m/1d42865c91404f46af4562532fdbea31@G08CNEXMBPEKD05.g08.fujitsu.local
* Allow configurable LZ4 TOAST compression.Robert Haas2021-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is now a per-column COMPRESSION option which can be set to pglz (the default, and the only option in up until now) or lz4. Or, if you like, you can set the new default_toast_compression GUC to lz4, and then that will be the default for new table columns for which no value is specified. We don't have lz4 support in the PostgreSQL code, so to use lz4 compression, PostgreSQL must be built --with-lz4. In general, TOAST compression means compression of individual column values, not the whole tuple, and those values can either be compressed inline within the tuple or compressed and then stored externally in the TOAST table, so those properties also apply to this feature. Prior to this commit, a TOAST pointer has two unused bits as part of the va_extsize field, and a compessed datum has two unused bits as part of the va_rawsize field. These bits are unused because the length of a varlena is limited to 1GB; we now use them to indicate the compression type that was used. This means we only have bit space for 2 more built-in compresison types, but we could work around that problem, if necessary, by introducing a new vartag_external value for any further types we end up wanting to add. Hopefully, it won't be too important to offer a wide selection of algorithms here, since each one we add not only takes more coding but also adds a build dependency for every packager. Nevertheless, it seems worth doing at least this much, because LZ4 gets better compression than PGLZ with less CPU usage. It's possible for LZ4-compressed datums to leak into composite type values stored on disk, just as it is for PGLZ. It's also possible for LZ4-compressed attributes to be copied into a different table via SQL commands such as CREATE TABLE AS or INSERT .. SELECT. It would be expensive to force such values to be decompressed, so PostgreSQL has never done so. For the same reasons, we also don't force recompression of already-compressed values even if the target table prefers a different compression method than was used for the source data. These architectural decisions are perhaps arguable but revisiting them is well beyond the scope of what seemed possible to do as part of this project. However, it's relatively cheap to recompress as part of VACUUM FULL or CLUSTER, so this commit adjusts those commands to do so, if the configured compression method of the table happens not to match what was used for some column value stored therein. Dilip Kumar. The original patches on which this work was based were written by Ildus Kurbangaliev, and those were patches were based on even earlier work by Nikita Glukhov, but the design has since changed very substantially, since allow a potentially large number of compression methods that could be added and dropped on a running system proved too problematic given some of the architectural issues mentioned above; the choice of which specific compression method to add first is now different; and a lot of the code has been heavily refactored. More recently, Justin Przyby helped quite a bit with testing and reviewing and this version also includes some code contributions from him. Other design input and review from Tomas Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander Korotkov, and me. Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
* Avoid repeated decoding of prepared transactions after a restart.Amit Kapila2021-03-01
| | | | | | | | | | | | | | | | | | | | In commit a271a1b50e, we allowed decoding at prepare time and the prepare was decoded again if there is a restart after decoding it. It was done that way because we can't distinguish between the cases where we have not decoded the prepare because it was prior to consistent snapshot or we have decoded it earlier but restarted. To distinguish between these two cases, we have introduced an initial_consistent_point at the slot level which is an LSN at which we found a consistent point at the time of slot creation. This is also the point where we have exported a snapshot for the initial copy. So, prepare transaction prior to this point are sent along with commit prepared. This commit bumps SNAPBUILD_VERSION because of change in SnapBuild. It will break existing slots which is fine in a major release. Author: Ajin Cherian, based on idea by Andres Freund Reviewed-by: Amit Kapila and Vignesh C Discussion: https://postgr.es/m/d0f60d60-133d-bf8d-bd70-47784d8fabf3@enterprisedb.com
* Simplify printing of LSNsPeter Eisentraut2021-02-23
| | | | | | | | | | Add a macro LSN_FORMAT_ARGS for use in printf-style printing of LSNs. Convert all applicable code to use it. Reviewed-by: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/CAExHW5ub5NaTELZ3hJUCE6amuvqAtsSxc7O+uK7y4t9Rrk23cw@mail.gmail.com
* Fix an oversight in ReorderBufferFinishPrepared.Amit Kapila2021-02-23
| | | | | | | | | We don't have anything to decode in a transaction if ReorderBufferTXN doesn't exist by the time we decode the commit prepared. So don't create a new ReorderBufferTXN here. This is an oversight in commit a271a1b5. Reported-by: Markus Wanner Discussion: https://postgr.es/m/dbec82e2-dbd7-95a2-c6b6-e488cbbdf853@bluegap.ch
* Fix typo in reorderbuffer.c.Amit Kapila2021-01-05
| | | | | | Author: Zhijie Hou Reviewed-by: Sawada Masahiko Discussion: https://postgr.es/m/ba88bb58aaf14284abca16aec04bf279@G08CNEXMBPEKD05.g08.fujitsu.local
* Allow decoding at prepare time in ReorderBuffer.Amit Kapila2021-01-04
| | | | | | | | | | | | | | | | | | | | | | | This patch allows PREPARE-time decoding of two-phase transactions (if the output plugin supports this capability), in which case the transactions are replayed at PREPARE and then committed later when COMMIT PREPARED arrives. Now that we decode the changes before the commit, the concurrent aborts may cause failures when the output plugin consults catalogs (both system and user-defined). We detect such failures with a special sqlerrcode ERRCODE_TRANSACTION_ROLLBACK introduced by commit 7259736a6e and stop decoding the remaining changes. Then we rollback the changes when rollback prepared is encountered. Author: Ajin Cherian and Amit Kapila based on previous work by Nikhil Sontakke and Stas Kelvich Reviewed-by: Amit Kapila, Peter Smith, Sawada Masahiko, Arseny Sher, and Dilip Kumar Tested-by: Takamichi Osumi Discussion: https://postgr.es/m/02DA5F5E-CECE-4D9C-8B4B-418077E2C010@postgrespro.ru https://postgr.es/m/CAMGcDxeqEpWj3fTXwqhSwBdXd2RS9jzwWscO-XbeCfso6ts3+Q@mail.gmail.com
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Update comment atop of ReorderBufferQueueMessage().Amit Kapila2020-12-19
| | | | | | | | | | The comments atop of this function describes behaviour in case of a transactional WAL message only, but it accepts both transactional and non-transactional WAL messages. Update the comments to describe behaviour in case of non-transactional WAL message as well. Ashutosh Bapat, rephrased by Amit Kapila Discussion: https://postgr.es/m/CAGEoWWTTzNzHOi8bj0wfAo1siGi-YEh6wqH1oaz4DrkTJ6HbTQ@mail.gmail.com
* Improve hash_create()'s API for some added robustness.Tom Lane2020-12-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Invent a new flag bit HASH_STRINGS to specify C-string hashing, which was formerly the default; and add assertions insisting that exactly one of the bits HASH_STRINGS, HASH_BLOBS, and HASH_FUNCTION be set. This is in hopes of preventing recurrences of the type of oversight fixed in commit a1b8aa1e4 (i.e., mistakenly omitting HASH_BLOBS). Also, when HASH_STRINGS is specified, insist that the keysize be more than 8 bytes. This is a heuristic, but it should catch accidental use of HASH_STRINGS for integer or pointer keys. (Nearly all existing use-cases set the keysize to NAMEDATALEN or more, so there's little reason to think this restriction should be problematic.) Tweak hash_create() to insist that the HASH_ELEM flag be set, and remove the defaults it had for keysize and entrysize. Since those defaults were undocumented and basically useless, no callers omitted HASH_ELEM anyway. Also, remove memset's zeroing the HASHCTL parameter struct from those callers that had one. This has never been really necessary, and while it wasn't a bad coding convention it was confusing that some callers did it and some did not. We might as well save a few cycles by standardizing on "not". Also improve the documentation for hash_create(). In passing, improve reinit.c's usage of a hash table by storing the key as a binary Oid rather than a string; and, since that's a temporary hash table, allocate it in CurrentMemoryContext for neatness. Discussion: https://postgr.es/m/590625.1607878171@sss.pgh.pa.us
* Remove incorrect assertion in reorderbuffer.c.Amit Kapila2020-12-04
| | | | | | | | | | | | | | | | | We start recording changes in ReorderBufferTXN even before we reach SNAPBUILD_CONSISTENT state so that if the commit is encountered after reaching that we should be able to send the changes of the entire transaction. Now, while recording changes if the reorder buffer memory has exceeded logical_decoding_work_mem then we can start streaming if it is allowed and we haven't yet streamed that data. However, we must not allow streaming to start unless the snapshot has reached SNAPBUILD_CONSISTENT state. In passing, improve the comments atop ReorderBufferResetTXN to mention the case when we need to continue streaming after getting an error. Author: Amit Kapila Reviewed-by: Dilip Kumar Discussion: https://postgr.es/m/CAA4eK1KoOH0byboyYY40NBcC7Fe812trwTa+WY3jQF7WQWZbQg@mail.gmail.com
* Fix 'skip-empty-xacts' option in test_decoding for streaming mode.Amit Kapila2020-11-17
| | | | | | | | | | | | | | | In streaming mode, the transaction can be decoded in multiple streams and those streams can be interleaved with streams of other transactions. So, we can't remember the transaction's write status in the logical decoding context because that might get changed due to some other transactions and lead to wrong answers for 'skip-empty-xacts' option. We decided to keep each transaction's write status in the ReorderBufferTxn to avoid interleaved streams changing the status of some unrelated transactions. Diagnosed-by: Amit Kapila Author: Dilip Kumar Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CAA4eK1LR7=XNM_TLmpZMFuV8ZQpoxkem--NZJYf8YXmesbvwLA@mail.gmail.com
* Track statistics for streaming of changes from ReorderBuffer.Amit Kapila2020-10-29
| | | | | | | | | | | | | | | | | | | This adds the statistics about transactions streamed to the decoding output plugin from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats and call pg_stat_reset_replication_slot to reset the stats of a particular slot. Users can pass NULL in pg_stat_reset_replication_slot to reset stats of all the slots. Commit 9868167500 has added the basic infrastructure to capture the stats of slot and this commit extends the statistics collector to track additional information about slots. Bump the catversion as we have added new columns in the catalog entry. Author: Ajin Cherian and Amit Kapila Reviewed-by: Sawada Masahiko and Dilip Kumar Discussion: https://postgr.es/m/CAA4eK1+chpEomLzgSoky-D31qev19AmECNiEAietPQUGEFhtVA@mail.gmail.com
* Execute invalidation messages for each XLOG_XACT_INVALIDATIONS messageAmit Kapila2020-10-15
| | | | | | | | | | | | | | | | | | | | during logical decoding. Prior to commit c55040ccd0 we have no way of knowing the invalidations before commit. So, while decoding we use to execute all the invalidations at each command end as we had no way of knowing which invalidations happened before that command. Due to this, transactions involving large amounts of DDLs use to take more time and also lead to high CPU usage. But now we know specific invalidations at each command end so we execute only required invalidations. It has been observed that decoding of a transaction containing truncation of a table with 1000 partitions would be finished in 1s whereas before this patch it used to take 4-5 minutes. Author: Dilip Kumar Reviewed-by: Amit Kapila and Keisuke Kuroda Discussion: https://postgr.es/m/CANDwggKYveEtXjXjqHA6RL3AKSHMsQyfRY6bK+NqhAWJyw8psQ@mail.gmail.com
* Fix typos in logical.c and reorderbuffer.c.Amit Kapila2020-10-09
| | | | | Reviewed-by: Sawada Masahiko Discussion: https://postgr.es/m/CAA4eK1K6zTpuqf_d7wXCBjo_EF0_B6Fz3Ecp71Vq18t=wG-nzg@mail.gmail.com
* Track statistics for spilling of changes from ReorderBuffer.Amit Kapila2020-10-08
| | | | | | | | | | | | | | | This adds the statistics about transactions spilled to disk from ReorderBuffer. Users can query the pg_stat_replication_slots view to check these stats and call pg_stat_reset_replication_slot to reset the stats of a particular slot. Users can pass NULL in pg_stat_reset_replication_slot to reset stats of all the slots. This commit extends the statistics collector to track this information about slots. Author: Sawada Masahiko and Amit Kapila Reviewed-by: Amit Kapila and Dilip Kumar Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com
* Remove useless Assert.Tom Lane2020-08-09
| | | | | | | | Testing that an unsigned variable is >= 0 is pretty pointless, as noted by Coverity and numerous buildfarm members. In passing, add comment about new uses of "volatile" --- Coverity doesn't much like that either, but it seems probably necessary.
* Implement streaming mode in ReorderBuffer.Amit Kapila2020-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of serializing the transaction to disk after reaching the logical_decoding_work_mem limit in memory, we consume the changes we have in memory and invoke stream API methods added by commit 45fdc9738b. However, sometimes if we have incomplete toast or speculative insert we spill to the disk because we can't generate the complete tuple and stream. And, as soon as we get the complete tuple we stream the transaction including the serialized changes. We can do this incremental processing thanks to having assignments (associating subxact with toplevel xacts) in WAL right away, and thanks to logging the invalidation messages at each command end. These features are added by commits 0bead9af48 and c55040ccd0 respectively. Now that we can stream in-progress transactions, the concurrent aborts may cause failures when the output plugin consults catalogs (both system and user-defined). We handle such failures by returning ERRCODE_TRANSACTION_ROLLBACK sqlerrcode from system table scan APIs to the backend or WALSender decoding a specific uncommitted transaction. The decoding logic on the receipt of such a sqlerrcode aborts the decoding of the current transaction and continue with the decoding of other transactions. We have ReorderBufferTXN pointer in each ReorderBufferChange by which we know which xact it belongs to. The output plugin can use this to decide which changes to discard in case of stream_abort_cb (e.g. when a subxact gets discarded). We also provide a new option via SQL APIs to fetch the changes being streamed. Author: Dilip Kumar, Tomas Vondra, Amit Kapila, Nikhil Sontakke Reviewed-by: Amit Kapila, Kuntal Ghosh, Ajin Cherian Tested-by: Neha Sharma, Mahendra Singh Thalor and Ajin Cherian Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
* WAL Log invalidations at command end with wal_level=logical.Amit Kapila2020-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When wal_level=logical, write invalidations at command end into WAL so that decoding can use this information. This patch is required to allow the streaming of in-progress transactions in logical decoding.  The actual work to allow streaming will be committed as a separate patch. We still add the invalidations to the cache and write them to WAL at commit time in RecordTransactionCommit(). This uses the existing XLOG_INVALIDATIONS xlog record type, from the RM_STANDBY_ID resource manager (see LogStandbyInvalidations for details). So existing code relying on those invalidations (e.g. redo) does not need to be changed. The invalidations written at command end uses a new xlog record type XLOG_XACT_INVALIDATIONS, from RM_XACT_ID resource manager. See LogLogicalInvalidations for details. These new xlog records are ignored by existing redo procedures, which still rely on the invalidations written to commit records. The invalidations are decoded and accumulated in top-transaction, and then executed during replay.  This obviates the need to decode the invalidations as part of a commit record. Bump XLOG_PAGE_MAGIC, since this introduces XLOG_XACT_INVALIDATIONS. Author: Dilip Kumar, Tomas Vondra, Amit Kapila Reviewed-by: Amit Kapila Tested-by: Neha Sharma and Mahendra Singh Thalor Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
* Adjust minor comment in reorderbuffer.c.Amit Kapila2020-07-18
| | | | | | Author: Dave Cramer Reviewed-by: David G. Johnston Discussion: https://postgr.es/m/CADK3HHL8do4Fp1bsymgNasx375njV3AR7zY3UgYwzbL_Dx-n2Q@mail.gmail.com
* Fix comments in reorderbuffer.c.Amit Kapila2020-07-18
| | | | | | Author: Dave Cramer Reviewed-by: David G. Johnston Discussion: https://postgr.es/m/CADK3HHL8do4Fp1bsymgNasx375njV3AR7zY3UgYwzbL_Dx-n2Q@mail.gmail.com
* Revert "Track statistics for spilling of changes from ReorderBuffer".Amit Kapila2020-07-13
| | | | | | | | | | | | | | | | | | | | The stats with this commit was available only for WALSenders, however, users might want to see for backends doing logical decoding via SQL API. Then, users might want to reset and access these stats across server restart which was not possible with the current patch. List of commits reverted: caa3c4242c Don't call elog() while holding spinlock. e641b2a995 Doc: Update the documentation for spilled transaction statistics. 5883f5fe27 Fix unportable printf format introduced in commit 9290ad198. 9290ad198b Track statistics for spilling of changes from ReorderBuffer. Additionaly, remove the release notes entry for this feature. Backpatch-through: 13, where it was introduced Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com
* Remove extra whitespace in comments atop ReorderBufferCheckMemoryLimit.Amit Kapila2020-07-06
| | | | Backpatch-through: 13, where it was introduced