For the most part this is a direct migration of the Perl code into C except as noted below.
A backup can now be initiated from a linked directory. The link will not be stored in the manifest or recreated on restore. If a link or directory does not already exist in the restore location then a directory will be created.
The logic for creating backup labels has been improved and it should no longer be possible to get a backup label earlier than the latest backup even with timezone changes or clock skew. This has never been an issue in the field that we know of, but we found it in testing.
For online backups all times are fetched from the PostgreSQL primary host (before only copy start was). This doesn't affect backup integrity but it does prevent clock skew between hosts affecting backup duration reporting.
Archive copy now works as expected when the archive and backup have different compression settings, i.e. when one is compressed and the other is not. This was a long-standing bug in the Perl code.
Resume will now work even if hardlink settings have been changed.
Reviewed by Cynthia Shang.
Bug Fixes:
* Fix archive-push/archive-get when PGDATA is symlinked. These commands tried to use cwd() as PGDATA but this would disagree with the path configured in pgBackRest if PGDATA was symlinked. If cwd() does not match the pgBackRest path then chdir() to the path and make sure the next cwd() matches the result from the first call. (Reported by Stephen Frost, Milosz Suchy.)
* Fix reference list when backup.info is reconstructed in expire command. Since the backup command is still using the Perl version of reconstruct this issue will not express unless 1) there is a backup missing from backup.info and 2) the expire command is run directly instead of running after backup as usual. This unlikely combination of events means this is probably not a problem in the field.
* Fix segfault on unexpected EOF in gzip decompression. (Reported by Stephen Frost.)
82df7e6f and 9856fef5 updated tests that used test points in preparation for the feature not being available in the C code.
Since tests points are no longer used remove the infrastructure.
Also remove one stray --test option in mock/all that was essentially a noop but no longer works now that the option has been removed.
Archive check does not run when in offline backup mode but the option was set to true in the manifest. It's harmless since these options are informational only but it could cause confusion when debugging.
This expression determines which files contain page checksums but it was also including the directory above the relation directories. In a real PostgreSQL installation this not a problem because these directories don't contain any files.
However, our tests place a file in `base` which the Perl code thought should have page checksums while the new C code says no.
Update the expression to document the change and avoid churn in the expect logs later.
Bug Fixes:
* Fix remote timeout in delta restore. When performing a delta restore on a largely unchanged cluster the remote could timeout if no files were fetched from the repository within protocol-timeout. Add keep-alives to prevent remote timeout. (Reported by James Sewell, Jens Wilke.)
* Fix handling of repeated HTTP headers. When HTTP headers are repeated they should be considered equivalent to a single comma-separated header rather than generating an error, which was the prior behavior. (Reported by donicrosby.)
Improvements:
* JSON output from the info command is no longer pretty-printed. Monitoring systems can more easily ingest the JSON without linefeeds. External tools such as jq can be used to pretty-print if desired. (Contributed by Cynthia Shang.)
* The check command is implemented entirely in C. (Contributed by Cynthia Shang.)
Documentation Improvements:
* Document how to contribute to pgBackRest. (Contributed by Cynthia Shang.)
* Document maximum version for auto-stop option. (Contributed by Brad Nicholson.)
Test Suite Improvements:
* Fix container test path being used when --vm=none. (Suggested by Stephen Frost.)
* Fix mismatched timezone in expect test. (Suggested by Stephen Frost.)
* Don't autogenerate embedded libc code by default. (Suggested by Stephen Frost.)
Note that building the manifest on each host has been temporarily removed.
This feature will likely be brought back as a non-default option (after the manifest code has been fully migrated to C) since it can be fairly expensive.
Features:
* PostgreSQL 12 support.
* Add info command set option for detailed text output. The additional details include databases that can be used for selective restore and a list of tablespaces and symlinks with their default destinations. (Contributed by Cynthia Shang. Suggested by Stephen Frost, ejberdecia.)
* Add standby restore type. This restore type automatically adds standby_mode=on to recovery.conf for PostgreSQL < 12 and creates standby.signal for PostgreSQL ≥ 12, creating a common interface between PostgreSQL versions. (Reviewed by Cynthia Shang.)
Improvements:
* The restore command is implemented entirely in C. (Reviewed by Cynthia Shang.)
Documentation Improvements:
* Document the relationship between db-timeout and protocol-timeout. (Contributed by Cynthia Shang. Suggested by James Chanco Jr.)
* Add documentation clarifications regarding standby repositories. (Contributed by Cynthia Shang.)
* Add FAQ for time-based Point-in-Time Recovery. (Contributed by Cynthia Shang.)
Recovery settings are now written into postgresql.auto.conf instead of recovery.conf. Existing recovery_target* settings will be commented out to help avoid conflicts.
A comment is added before recovery settings to identify them as written by pgBackRest since it is unclear how, in general, old settings will be removed.
recovery.signal and standby.signal are automatically created based on the recovery settings.
This restore type automatically adds standby_mode=on to recovery.conf.
This could be accomplished previously by setting --recovery-option=standby_mode=on but PostgreSQL 12 requires standby mode to be enabled by a special file named standby.signal.
The new restore type allows us to maintain a common interface between PostgreSQL versions.
For the most part this is a direct migration of the Perl code into C.
There is one important behavioral change with regard to how file permissions are handled. The Perl code tried to set ownership as it was in the manifest even when running as an unprivileged user. This usually just led to errors and frustration.
The C code works like this:
If a restore is run as a non-root user (the typical scenario) then all files restored will belong to the user/group executing pgBackRest. If existing files are not owned by the executing user/group then an error will result if the ownership cannot be updated to the executing user/group. In that case the file ownership will need to be updated by a privileged user before the restore can be retried.
If a restore is run as the root user then pgBackRest will attempt to recreate the ownership recorded in the manifest when the backup was made. Only user/group names are stored in the manifest so the same names must exist on the restore host for this to work. If the user/group name cannot be found locally then the user/group of the PostgreSQL data directory will be used and finally root if the data directory user/group cannot be mapped to a name.
Reviewed by Cynthia Shang.
These features finally make the ls command practical.
Currently the JSON contains only name, type, and size. We may add more fields in the future, but these seem like the minimum needed to be useful.
Bug Fixes:
* Improve slow manifest build for very large quantities of tables/segments. (Reported by Jens Wilke.)
* Fix exclusions for special files. (Reported by CluelessTechnologist, Janis Puris, Rachid Broum.)
Improvements:
* The stanza-create/update/delete commands are implemented entirely in C. (Contributed by Cynthia Shang.)
* The start/stop commands are implemented entirely in C. (Contributed by Cynthia Shang.)
* Create log directories/files with 0750/0640 mode. (Suggested by Damiano Albani.)
Documentation Bug Fixes:
* Fix yum.p.o package being installed when custom package specified. (Reported by Joe Ayers, John Harvey.)
Documentation Improvements:
* Build pgBackRest as an unprivileged user. (Suggested by Laurenz Albe.)
Decoding a manifest from the JSON provided by C to the hash required by Perl is an expensive process. If manifest() was called on a remote it was being decoded into a hash and then immediately re-encoded into JSON for transmission over the protocol layer.
Instead, provide a function for the remote to get the raw JSON which can be transmitted as is and decoded in the calling process instead.
This makes remote manifest calls as fast as they were before 2.16, but local calls must still pay the decoding penalty and are therefore slower. This will continue to be true until the Perl storage interface is retired at the end of the C migration.
Note that for reasonable numbers of tables there is no detectable difference. The case in question involved 250K tables with a 10 minute decode time (which was being doubled) on a fast workstation.
Prior to 2.16 the Perl manifest code would skip any file that began with a dot. This was not intentional but it allowed PostgreSQL socket files to be located in the data directory. The new C code in 2.16 did not have this unintentional exclusion so socket files in the data directory caused errors.
Worse, the file type error was being thrown before the exclusion check so there was really no way around the issue except to move the socket files out of the data directory.
Special file types (e.g. socket, pipe) will now be automatically skipped and a warning logged to notify the user of the exclusion. The warning can be suppressed with an explicit --exclude.
Reported by CluelessTechnologist, Janis Puris, Rachid Broum.
Putting the checksum at the beginning of the file made it impossible to stream the file out when saving. The entire file had to be held in memory while it was checksummed so the checksum could be written at the beginning.
Instead place the checksum at the end. This does not break the existing Perl or C code since the read is not order dependent.
There are no plans to improve the Perl code to take advantage of this change, but it will make the C implementation more efficient.
Reviewed by Cynthia Shang.
The log directories/files were being created with a mix of modes depending on whether they were created in C or Perl. In particular, the C code was creating log files with the execute bit set for the user and group which was just odd.
Standardize on 750/640 for both code paths.
Suggested by Damiano Albani.
The Perl versions remain because they are still being used by the Perl stanza commands. Once the stanza commands are migrated they can be removed.
Contributed by Cynthia Shang.
Bug Fixes:
* Retry S3 RequestTimeTooSkewed errors instead of immediately terminating. (Reported by sean0101n, Tim Garton, Jesper St John, Aleš Zelený.)
* Fix incorrect handling of transfer-encoding response to HEAD request. (Reported by Pavel Suderevsky.)
* Fix scoping violations exposed by optimizations in gcc 9. (Reported by Christian Lange, Ned T. Crigler.)
Features:
* Add repo-s3-port option for setting a non-standard S3 service port.
Improvements:
* The local command for backup is implemented entirely in C. (Contributed by David Steele, Cynthia Shang.)
* The check command is implemented partly in C. (Reviewed by Cynthia Shang.)
Implement switch WAL and archive check in C but leave the rest in Perl for now.
The main idea was to have some real integration tests for the new database code so the rest of the migration can wait.
Reviewed by Cynthia Shang.
If this option is set then ports appended to repo-s3-endpoint or repo-s3-host will be ignored.
Setting this option explicitly may be the only way to use a bare ipv6 address with S3 (since multiple colons confuse the parser) but we plan to improve this in the future.
The local process is now entirely migrated to C. Since all major I/O operations are performed in the local process, the vast majority of I/O is now performed in C.
Contributed by David Steele, Cynthia Shang.
For offline backups the upper bound was being set to 0x0000FFFF0000FFFF rather than UINT64_MAX. This meant that page checksum errors might be ignored for databases with a lot of past WAL in offline mode.
Online mode is not affected since the upper bound is retrieved from pg_start_backup().
Since 2.91 JSON::PP has a bias for saving variables that look like numbers as numbers even if they were declared as strings.
Force versions to strings where needed by appending ''.
Update the json-pp-perl package on Ubuntu 18.04 to 2.97 to provide test coverage.
No new Perl code is being developed, so these tools are just taking up time and making migrations to newer platforms harder. There are only a few Perl tests remaining with full coverage so the coverage tool does not warn of loss of coverage in most cases.
Remove both tools and associated libraries.
Maintaining the storage layer/drivers in two languages is burdensome. Since the integration tests require the Perl storage layer/drivers we'll need them even after the core code is migrated to C. Create an interface layer so the Perl code can be removed and new storage drivers/features introduced without adding Perl equivalents.
The goal is to move the integration tests to C so this interface will eventually be removed. That being the case, the interface was designed for maximum compatibility to ease the transition. The result looks a bit hacky but we'll improve it as needed until it can be retired.
Bug Fixes:
* Fix archive retention expiring too aggressively. (Fixed by Cynthia Shang. Reported by Mohamad El-Rifai.)
Improvements:
* The expire command is implemented entirely in C. (Contributed by Cynthia Shang.)
* The local command for restore is implemented entirely in C.
* Remove hard-coded PostgreSQL user so $PGUSER works. (Suggested by Julian Zhang, Janis Puris.)
* Honor configure --prefix option. (Suggested by Daniel Westermann.)
* Rename repo-s3-verify-ssl option to repo-s3-verify-tls. The new name is preferred because pgBackRest does not support any SSL protocol versions (they are all considered to be insecure). The old name will continue to be accepted.
Documentation Improvements:
* Add FAQ to the documentation. (Contributed by Cynthia Shang.)
* Use wal_level=replica in the documentation for PostgreSQL ≥ 9.6. (Suggested by Patrick McLaughlin.)
This implementation duplicates the functionality of the Perl code but does so with different logic and includes full unit tests.
Along the way at least one bug was fixed, see issue #748.
Contributed by Cynthia Shang.
The PostgreSQL user was hard-coded to the OS user which libpq will automatically use if $PGUSER is not set, so this code was redundant and prevented $PGUSER from working when set.
Suggested by Julian Zhang, Janis Puris.
This was not enforced at parse time because repo1-cipher-type could be passed on the command-line even in cases where encryption was not needed by the subprocess.
Filter repo-cipher-type so it is never passed on the command line. If the subprocess does not have access to the passphrase then knowing the encryption type is useless anyway.
