Update references to recovery.conf to include postgresql.auto.conf used in newer versions.
Also update a broken recovery URL and point it to the current version (with a hint to select the proper version of PostgreSQL).
c8264291 added libbacktrace to the meson build (not used in production yet), but held off on adding it to autoconf/make before more performance testing was done.
Performance tests show there is no noticeable cost to adding libbacktrace, so add it to get more detail error stack traces.
It is a bit confusing that --help and --version do not work like most command-line programs. For example, git allows either --help or help.
Make these work by making them shortcuts (not actual options) to the applicable commands.
The user will still need to use help (not --help) to get help on specific commands/options, but at least they can get to the main help (which will tell them this) via --help.
Bug Fixes:
* Fix short read in block incremental restore. (Reviewed by Stephen Frost, Brent Graveland. Reported by Adol Rodriguez, Brent Graveland.)
* Fix overflow suppressing backup progress in info output. (Fixed by Robert Donovan. Reviewed by Joe Wildish.)
Improvements:
* Preserve partial files during block incremental delta restore. (Reviewed by Stephen Frost.)
* Add support for alternate compile-time page sizes. (Contributed by Viktor Kurilko. Reviewed by David Steele.)
* Skip files truncated during backup when bundling. (Contributed by Georgy Shelkovy. Reviewed by David Steele.)
* Improve SFTP storage error messages. (Contributed by Reid Thompson. Reviewed by David Steele.)
Use storageSftpEvalLibSsh2Error() in more locations to provide better error information. Also add storageSftpLibSsh2SessionLastError() for the same reason.
During restore it is possible to read all the blocks out of a compressed super block without reading all the input. This is because the compression format may have some trailing bytes that are not required for decompression but are required to indicate that data has ended. If a buffer aligned with the compressed data in a certain way, these last bytes might not be read.
Explicitly read out any final bytes at the end of each super block to handle this case. This should always result in no additional data out and we check for that, but it does move the read position to the beginning of the next compressed super block so decompression can begin without error.
Refactor 02eea555 to always close the file immediately on EOF and use backupCopyResultCopy to continue processing. Closing the file immediately saves a later EOF check and is friendlier to added logic in this area. Using backupCopyResultCopy to continue is clearer also makes it easier to add new logic.
Also store zero checksum so the bulk of results collection can be moved within the copy block.
This allows less duplication of buffers.
For delta check return file->pgFileSize/file->pgFileChecksum instead of pgTestSize/pgTestChecksum since this saves one buffer duplication and we know these values are equal since we just checked them.
Also add an assert to ensure copyChecksum is valid relative to size.
If a file stored with block incremental shrinks below the prior block size then the map is useless and the entire file needs to be stored again.
In this case use the new block incremental values (even if none) rather than preserving the old ones.
Previously files that were smaller than the expected size were not preserved for block incremental, even though it is possible that block incremental could make use of a partial file.
One example is when a restore encounters an error. On retry the partial file can be used as a starting point rather than copying again from the beginning. Another example is restoring a backup where a file is larger than what already exists in the data directory.
Preserve any size file when block incremental will be used for the delta in order to reuse partial files when possible. If the file is smaller than expected then disable the whole-file checksum to reduce overhead.
This refactor should provide more clarity on what factors affect an incremental, rather that just having one big expression do it all. Overall this may be slightly more efficient since some values are reused that before were recalculated.
No behavioral changes are introduced.
Writing the sz and szCplt parameters in the lock file used jsonWriteUInt64() but reading these parameters used jsonReadUInt(). This caused a silent exception for any backups larger than MAX_UINT and prevented the info command from reporting progress.
Correct this so the reads are symmetric and verified before/after with a test.
In bundle mode pgBackRest skips files of zero size, that is, it does not queue them for copying.
After splitting the files into bundles, pgBackRest launches one or more processes that directly perform the backup, namely, read the files and, if necessary, write them to the bundles.
If during the time between the distribution of all files among bundles and the direct copying of a file to a bundle, this file of non-zero size was truncated to zero size (for example, when the table was truncated), then pgBackRest still unconditionally places such a zero-size file in the bundle, taking up space in it equal to the size of the headings, and additionally writes the original file size to the manifest.
In debug build an assertion was added, that does not allow zero-size files to be written to bundles, which leads to an error.
To solve the problem, this patch, when reading the next file, loads one buffer from the file to detect if it is zero-size. If so it marks the file as truncated and continues on to the next file.
The advantages of the solution are that, firstly, the assert will not fire on debug builds, and secondly, we will not place zero-size files in bundles, which exactly corresponds to the specification.
The patch adds the backupCopyResultTruncate value to the BackupCopyResult enumeration to use it to indicate the result when a non-zero size file is truncated to zero size during the backup process.
Alternate pages sizes can be selected at compile-time, .e.g. 4096. While compile-time settings are generally not well tested by core, some established forks such as Greenplum use them.
Bug Fixes:
* Fix regression in retries. (Reviewed by Stephen Frost. Reported by Norman Adkins, Tanel Suurhans, Jordan English, Timothée Peignier.)
* Fix recursive path remove in SFTP storage driver. (Fixed by Reid Thompson. Reviewed by Stephen Frost. Reported by Luc.)
Improvements:
* Remove support for PostgreSQL 9.3. (Reviewed by Stephen Frost.)
Documentation Features:
* Document maintainer options. (Reviewed by Stefan Fercot.)
* Update point-in-time recovery documentation for PostgreSQL >= 13.
Test Suite Improvements:
* Allow config/load unit test to run without libssh2 installed. (Contributed by Reid Thompson. Reviewed by David Steele. Suggested by Wu Ning.)
These fields were not used because of the noop so it was hard to keep them up to date. Rather than attempt to do so, just remove them and add a comment to explain why they are missing.
storageSftpPathRemove() used LIBSSH2_FX_FAILURE to determine when it was attempting to unlink a directory, but it appears that LIBSSH2_FX_PERMISSION_DENIED is also valid for this case.
Update storageSftpPathRemove() to accept either error and adjust tests.
PITR changed in PostgreSQL 13 to error when the recovery target is not reached. Update the documentation to work with PostgreSQL >= 13 as well as < 13.
Also update the versions built for RHEL and Debian since PostgreSQL 11 is now EOL.
Per our policy to support five EOL versions of PostgreSQL, 9.3 is no longer supported by pgBackRest.
Remove all logic associated with 9.3 and update the tests.
5314dbf aimed to make nested Wait objects more accurate with regard to wait time but it also got rid of the "bonus" retry that was implicit in the prior implementation. This meant that if an operation used up the entire allotted timeout, it would not be retried. Object stores especially are noisy places and some amount of retry should always be attempted. So even though removing the "bonus" retry was intended, it turned out not to be a good idea.
Instead of an implicit retry, formalize two retries in the Wait object even if the wait time has expired. Any number of retries are allowed during the wait period. Also remove waitRemaining() since it is no longer needed.
Adjust tests as needed to account for the extra timeouts.
Note that there may still be an underlying issue here that is simply being masked by retries. That is, the issue expressing was that waiting for a socket to be writable was timing out and without a retry that caused a hard error. This patch does nothing to address the source of the write timeout and perhaps there is nothing we can do about it. It does seem similar to the write issue we had with our blocking TLS implementation, but it was never clear if that was a problem with TLS, the kernel, or a bug in pgBackRest itself. It cropped up after a kernel update and we switched to non-blocking TLS to address the issue (c88684e).
The pq scripts were pretty static which had already led to a lot of code duplication in the backup test harness.
Instead allow the scripts to be built dynamically, which allows for much more flexibility and reduces duplication. For now just make these changes in the backup harness, but they may be useful elsewhere.
While we are making big changes, also update the macro/function names to hew closer to our current harness naming conventions.
Document maintainer options in a separate section with appropriate explanation and caveats.
Also make the pg-version-force option user visible now that maintainer caveats have been documented.
The reference documentation was still using a very old version of rendering from before the user guide was introduced. This was preserved in the initial C migration to reduce the diff between Perl and C for testing purposes. The old version used hard linefeeds to simulate paragraphs and reduce the amount of markup that needed to be used. In retrospect this was not a great idea.
Instead use more natural rendering that does not depend on using hard linefeeds between paragraphs.
For some reason the internal section id was included in the title. This was probably copied from another section title where it made more sense, e.g. including the option name after the title.
Also add release note missed in 1eb01622.
Migrate generation of these files from help.xml to the intermediate documentation format. This allows us to share a lot of code that is already in C and remove duplicated code in Perl. More duplicate code can be removed in Perl once man generation is migrated.
Also update the unit test harness to allow testing of modules in the doc directory.
The help source file had previously been hardcoded and now that is no longer needed.
A future commit will introduce more sources outside of the xml path.
Bug Fixes:
* Fix issue restoring block incremental without a block list. (Reviewed by Stephen Frost, Burak Yurdakul. Reported by Burak Yurdakul.)
Features:
* Add --repo-storage-tag option to create object tags. (Reviewed by Stephen Frost, Stefan Fercot, Timothée Peignier.)
* Add known hosts checking for SFTP storage driver. (Contributed by Reid Thompson. Reviewed by Stephen Frost, David Steele.)
* Support for dual stack connections. (Reviewed by Stephen Frost.)
* Add backup size completed/total to info command JSON output. (Contributed by Stefan Fercot. Reviewed by David Steele.)
Improvements:
* Multi-stanza check command. (Reviewed by Stephen Frost.)
* Retry reads of pg_control until checksum is valid. (Reviewed by Stefan Fercot, Stephen Frost.)
* Optimize WAL segment check after successful backup. (Reviewed by Stephen Frost.)
* Improve GCS multi-part performance. (Reviewed by Reid Thompson.)
* Allow archive-get command to run when stanza is stopped. (Reviewed by Tom Swartz, David Christensen, Reid Thompson.)
* Accept leading tilde in paths for SFTP public/private keys. (Contributed by Reid Thompson. Reviewed by David Steele.)
* Reload GCS credentials before renewing authentication token. (Reviewed by Stephen Frost. Suggested by Daniel Farina.)
Documentation Bug Fixes:
* Fix configuration reference example for the tls-server-address option. (Fixed by Hartmut Goebel. Reviewed by David Steele.)
* Fix command reference example for the filter option.
Test Suite Improvements:
* Allow storage/sftp unit test to run without libssh2 installed. (Contributed by Reid Thompson. Reviewed by David Steele. Suggested by Wu Ning.)
This example was broken by 24f7252. Revert to (almost) the prior code to fix this example until something better can be committed. The something better is in progress but it adds new build requirements so it is too late to include it for the release.
Technically this breaks some other examples, but they are all internal and not visible in the user-facing documentation.
It is currently possible for a block map to be written without any accompanying blocks. This happens when a file timestamp is updated but the file has not changed. On restore, this caused problems when encryption was enabled, the block map was bundled after a file that had been stored without block incremental, and both files were included in a single bundle read. In this case the block map would not be decrypted and the encrypted data was passed to blockMapNewRead() with unpredictable results. In many cases built-in retries would rectify this problem as long as delta was enabled since block maps would move to the beginning of the bundle read and be decrypted properly. If enough files were affected, however, it could overwhelm the retries and throw an error. Subsequent delta restores would eventually be able to produce a valid result.
Fix this by moving block map decryption so it works correctly no matter where the block map is located in the read. This has the additional benefit of limiting how far the block map can read so it will error earlier if corrupt. Though in this case there was no repository corruption involved, it appeared that way to blockMapNewRead() since it was reading encrypted data.
Arguably block maps without blocks should not be written at all, but it would be better to consider that as a separate change. This pattern clearly exists in the wild and needs to be handled, plus the new implementation has other benefits.
By default require a known hosts match as part of the SFTP storage driver's authentication process, i.e. repo-sftp-host-key-check-type=strict. The match is expected to be found in the default list or in a list of known hosts files provided by the user. An exception is made if a fingerprint has been manually configured with repo-sftp-host-fingerprint or repo-sftp-host-key-check-type=accept-new can be used to automatically add new hosts.
Also allow host key verification to be skipped, as before, but require the user to explicitly set this (repo-sftp-host-key-check-type=none) rather than it being the default.
This option is intended to eventually create a comprehensive report about the state of the pgBackRest configuration based on the results of the check command.
Implement a detailed report of the configuration options in the environment and configuration files. This should be useful information when debugging configuration errors, since invalid options and configurations are automatically noted. While custom config locations will not be found automatically, it will at least be clear that the config is not in a standard location.
For now keep this option internal since there is a lot of work to be done, but commit it so that it can be used when needed and tested in various environments.
Note that for now when --report is specified, the check command is not being run at all. Only the config report is generated. This behavior will be improved in the future.
This new option allows tags to be added to objects in S3, GCS, and Azure repositories.
This was fairly straightforward for S3 and Azure, but GCS does not allow tags for a simple upload using the JSON interface. If tags are required then the resumable interface must be used even if the file falls below the limit that usually triggers a resumable upload (i.e. size < repo-storage-upload-chunk-size).
This option is structured so that tags must be specified per-repo rather than globally for all repos. This seems logical since the tag keys and values may vary by service, e.g. S3 vs GCS.
These storage tags are independent of backup annotations since they are likely to be used for different purposes, e.g. billing, while the backup annotations are primarily intended for monitoring.
The prior code would only connect to the first address provided by getaddrinfo().
Instead try each address in the list. If all connections fail then wait and try them all again until timeout.
Currently a round robin approach is used where each connection attempt must fail before the next connection is attempted. This works fine, for example, when an ipv6 address has no route to the host, but will work less well when a host answers but doesn't respond in a timely fashion.
We may consider a Happy Eyeballs approach in the future, but since pgBackRest is primarily a background process, it is not clear that slightly improved response time (in the case of failed connections) is worth the extra complexity.
The prior code did one list command against the storage for each WAL segment. This led to a lot of lists and was especially inefficient when the WAL (or the majority of it) was already present.
Optimize to keep the contents of a WAL directory and use them on a subsequent search. Leave the optimizations for a single WAL segment since other places still use that mode.
On certain file systems (e.g. ext4) pg_control may appear torn if there is a concurrent write while reading the file. To prevent an invalid read, retry until the checksum matches the control data.
Special handling is required for the pg-version-force feature since the offset of the checksum is not known. In this case, scan from the default position to the end of the data looking for a checksum match. This is a bit imprecise, but better than nothing, and the chance of a random collision in the control data seems very remote considering the ratio of data size (< 512 bytes) to checksum size (4 bytes).
This was discovered and a possible solution proposed for PostgreSQL in [1]. The proposed solution may work for backup, but pgBackRest needs to be able to read pg_control reliably outside of backup. So no matter what fix is adopted for PostgreSQL, pgBackRest need retries. Further adjustment may be required as the PostgreSQL fix evolves.
[1] https://www.postgresql.org/message-id/20221123014224.xisi44byq3cf5psi%40awork3.anarazel.de
The prior example (::*) was not valid and would result in the following error:
ERROR: [049]: unable to get address for '::*': [-2] Name or service not known
Correct values are either * for IPv4 or :: for IPv6. The IPv4 value is used as the example since only one example is allowed.
