Currently each module that needs to collect statistics implements custom code to do so. This is cumbersome.
Create a general purpose module for collecting and reporting statistics. Statistics are output in the log at detail level, but there are other uses they could be put to eventually.
No new functionality is added. This is just a drop-in replacement for the current statistics, with the advantage of being more flexible.
The new stats are slower because they involve a list lookup, but performance testing shows stats can be updated at about 40,000/ms which seems fast enough for our purposes.
This aligns better with general PostgreSQL usage and our own documentation (updated in 4bcef702).
Usage in the backup.manifest tests has not been updated since it might break the file format.
Rather than bS3 use strStorage which can indicate more than two storage types.
For the moment there are still only two storage types but this change is required before more can be added.
The --repo-retention-full-type option allows retention of full backups based on a time period, specified in days.
The new option will default to 'count' and therefore will not affect current installations. Setting repo-retention-full-type to 'time' will allow the user to use a time period, in days, to indicate full backup retention. Using this method, a full backup can be expired only if the time the backup completed is older than the number of days set with repo-retention-full (calculated from the moment the 'expire' command is run) and at least one full backup meets the retention period. If archive retention has not been configured, then the default settings will expire archives that are prior to the oldest retained full backup. For example, if there are three full backups ending in times that are 25 days old (F1), 20 days old (F2) and 10 days old (F3), then if the full retention period is 15 days, then only F1 will be expired; F2 will be retained because F1 is not at least 15 days old.
LZ4 compresses data faster than gzip but at a lower ratio. This can be a good tradeoff in certain scenarios.
Note that setting compress-type=lz4 will make new backups and archive incompatible (unrestorable) with prior versions of pgBackRest.
Add compress-type option and deprecate compress option. Since the compress option is boolean it won't work with multiple compression types. Add logic to cfgLoadUpdateOption() to update compress-type if it is not set directly. The compress option should no longer be referenced outside the cfgLoadUpdateOption() function.
Add common/compress/helper module to contain interface functions that work with multiple compression types. Code outside this module should no longer call specific compression drivers, though it may be OK to reference a specific compression type using the new interface (e.g., saving backup history files in gz format).
Unit tests only test compression using the gz format because other formats may not be available in all builds. It is the job of integration tests to exercise all compression types.
Additional compression types will be added in future commits.
Most of these tests are just checking that errors are thrown when required. These are well covered in various unit tests.
The "cannot resume" tests are also well covered in the backup unit tests.
Finally, config warnings are well covered in the config unit tests.
There is more to be done here, but this accounts for the low-hanging fruit.
Set log-level-file=off when more that one test will run. In this case is it impossible to see the logs anyway since they will be automatically cleaned up after the test. This improves performance pretty dramatically since trace-level logging is expensive. If a singe integration test is run then log-level-file is trace by default but can be changed with the --log-level-test-file option.
Reduce buffer-size to 64k to save memory during testing and allow more processes to run in parallel.
Update log replacement rules so that these options can change without affecting expect logs.
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.
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.
Test points will not be available in the C code so update these tests as best as possible without using them.
This represents a loss of coverage for the Perl code (soon to be removed) which will be made up in the C code with unit tests.
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.
The protocol timeout tests have been superceded by unit tests.
The TEST_BACKUP_RESUME test point was incorrectly included into a number of tests, probably a copy pasto. It didn't hurt anything but it did add 200ms to each test where it appeared.
Catalog and control version tests were redundant. The database version and system id tests covered the important code paths and the C code gets these values from a lookup table.
Finally, fix an incomplete update to the backup.info file while munging for tests.
Previously, options were being filtered based on what was currently valid. For chained commands (e.g. backup then expire) some options may be valid for the first command but not the second.
Filter based on the command definition rather than what is currently valid to avoid logging options that are not valid for subsequent commands. This reduces the number of options logged and will hopefully help avoid confusion and expect log churn.
This user was created before we tested in containers to ensure isolation between the pg and repo hosts which were then just directories. The downside is that this resulted in a lot of sudos to set the pgbackrest user and to remove files which did not belong to the main test user.
Containers provide isolation without needing separate users so we can now safely remove the pgbackrest user. This allows us to remove most sudos, except where they are explicitly needed in tests.
While we're at it, remove the code that installed the Perl C library (which also required sudo) and simply add the build path to @INC instead.
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.
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.
Info files required three copies in memory to be loaded (the original string, an ini representation, and the final info object). Not only was this memory inefficient but the Ini object does sequential scans when searching for keys making large files very slow to load.
This has not been an issue since archive.info and backup.info are very small, but it becomes a big deal when loading manifests with hundreds of thousands of files.
Instead of holding copies of the data in memory, use a callback to deliver the ini data directly to the object when loading. Use a similar method for save to avoid having an intermediate copy. Save is a bit complex because sections/keys must be written in alpha order or older versions of pgBackRest will not calculate the correct checksum.
Also move the load retry logic to helper functions rather than embedding it in the Info object. This allows for more flexibility in loading and ensures that stack traces will be available when developing unit tests.
Reviewed by Cynthia Shang.
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.
Logging stayed in the backup log until the Perl code started. Fix this so it logs to the correct file and will still work after the Perl code is removed.
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().
ScalityS3 has not received any maintenance in years and is slow to start which is bad for testing. Replace it with minio which starts quickly and ships as a single executable or a tiny container.
Minio has stricter limits on allowable characters but should still provide enough coverage to show that our encoding is working correctly.
This commit also includes the upgrade to openssl 1.1.1 in the Ubuntu 18.04 container.
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.
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 C code is designed to be efficient rather than deterministic at the debug log level. As we move more testing from integration to unit tests it makes less sense to try and maintain the expect logs at this log level.
Most of the expect logs have already been moved to detail level but mock/all still had tests at debug level. Change the logging defaults in the config file and remove as many references to log-level-console as possible.
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.
This condition was not being properly checked for in the C code and it caused problems in the info command, at the very least.
Instead of applying a local fix, introduce a new path option type that will rigorously check the format of any incoming paths.
Reported by Marc Cousin.
Add the buffer-size, compress-level, compress-level-network, and process-max options to the backup:option section in backup.manifest to aid in debugging.
It may also make sense to propagate these options up to backup.info so they can be displayed in the info command, but for now this is deemed sufficient.
Contributed by blogh.
The same test configurations are run on all four test VMs, which seems a real waste of resources.
Vary the tests per VM to increase coverage while reducing the total number of tests. Be sure to include each major feature (remote, s3, encryption) in each VM at least once.
Replace the repository path with just "the repository". The path is not important in this context and it is clearer to state where the stanzas are missing from.
There are a number of cases where a checksum delta is more appropriate than the default time-based delta:
* Timeline has switched since the prior backup
* File timestamp is older than recorded in the prior backup
* File size changed but timestamp did not
* File timestamp is in the future compared to the start of the backup
* Online option has changed since the prior backup
A practical example is that checksum delta will be enabled after a failover to standby due to the timeline switch. In this case, timestamps can't be trusted and our recommendation has been to run a full backup, which can impact the retention schedule and requires manual intervention.
Now, a checksum delta will be performed if the backup type is incr/diff. This means more CPU will be used during the backup but the backup size will be smaller and the retention schedule will not be impacted.
Contributed by Cynthia Shang.
PostgreSQL 11 introduces configurable WAL segment sizes, from 1MB to 1GB.
There are two areas that needed to be updated to support this: building the archive-get queue and checking that WAL has been archived after a backup. Both operations require the WAL segment size to properly build a list.
Checking the archive after a backup is still implemented in Perl and has an active database connection, so just get the WAL segment size from the database.
The archive-get command does not have a connection to the database, so get the WAL segment size from pg_control instead. This requires a deeper inspection of pg_control than has been done in the past, so it seemed best to copy the relevant data structures from each version of PostgreSQL and build a generic interface layer to address them. While this approach is a bit verbose, it has the advantage of being relatively simple, and can easily be updated for new versions of PostgreSQL.
Since the integration tests generate pg_control files for testing, teach Perl how to generate files with the correct offsets for both 32-bit and 64-bit architectures.
Use checksums rather than timestamps to determine if files have changed. This is useful in cases where the timestamps may not be trustworthy, e.g. when performing an incremental after failing over to a standby.
If checksum delta is enabled then checksums will be used for verification of resumed backups, even if they are full. Resumes have always used checksums to verify the files in the repository, enabling delta performs checksums on the database files as well.
Note that the user must manually enable this feature in cases were it would be useful or just keep in enabled all the time. A future commit will address automatically enabling the feature in cases where it seems likely to be useful.
Contributed by Cynthia Shang.
% characters caused issues in backup/restore due to filenames being appended directly into a format string.
Reserved XML characters (<>&') caused issues in the S3 driver due to improper escaping.
Add a file with all common special characters to regression testing.
Previously an error would be generated if other files were present and not owned by the PostgreSQL user. This hasn't been a big deal in practice but it could cause issues.
Also add tests to make sure the same logic applies with links to files, i.e. all other files in the directory should be ignored. This was actually working correctly, but there were no tests for it before.
The log-subprocess feature added in 22765670 failed to take into account the naming for remote processes spawned by local processes. Not only was the local command used for the naming of log files but the process id was not pass through. This meant every remote log was named "[stanza]-local-remote-000" which is confusing and meant multiple processes were writing to the same log.
Instead, pass the real command and process id to the remote. This required a minor change in locking to ignore locks if process id is greater than 0 since remotes started by locals never lock.
Relative link paths were being combined with the paths of previous links (relative or absolute) due to the $strPath variable being modified in the current iteration rather than simply being passed to the next level of recursion.
This issue did not affect absolute links and relative tablespace links were caught by other checks, though the error was confusing.
Reported by Cynthia Shang.
