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.
Azure and Azure-compatible object stores can now be used for repository storage.
Currently only shared key authentication is supported but SAS will be added soon.
When uploading large files the upload is split into multiple parts which are assembled at the end to create the final file. Previously we waited until each part was acknowledged before starting on the processing (i.e. compression, etc.) of the next part.
Now, the request for each part is sent while processing continues and the response is read just before sending the request for the next part. This asynchronous method allows us to continue processing while the S3 server formulates a response.
Testing from outside AWS in a high-bandwidth, low-latency environment showed a 35% improvement in the upload time of 1GB files. The time spent waiting for multipart notifications was reduced by ~300% (this measurement included the final part which is not uploaded asynchronously).
There are still some possible improvements: 1) the creation of the multipart id could be made asynchronous when it looks like the upload will need to be multipart (this may incur cost if the upload turns out not to be multipart). 2) allow more than one async request (this will use more memory).
A fair amount of refactoring was required to make the HTTP responses asynchronous. This may seem like overkill but having well-defined request, response, and session objects will also be advantageous for the upcoming HTTP server functionality.
Another advantage is that the lifecycle of an HttpSession is better defined. We only want to reuse sessions that complete the request/response cycle successfully, otherwise we consider the session to be in a bad state and would prefer to start clean with a new one. Previously, this required complex notifications to mark a session as "successfully done". Now, ownership of the session is passed to the request and then the response and only returned to the client after a successful response. If an error occurs anywhere along the way the session will be automatically closed by the object destructor when the request/response object is freed (depending on which one currently owns the session).
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.
Previously when retention-archive was set (either by the user or by default), archives prior to the archive-start of the oldest remaining full backup (after backup expiration occurred) would be expired even though the retention-archive threshold had not been met. For example, if there were 1 full backup remaining after backup expiration and the retention-archive was set to 2 and retention-archive-type=full, then archives prior to the archive-start of the remaining full backup would still be removed even though retention-archive required 2 full backups remaining before archives should be expired.
The thought was to keep the archive directory clean and since the full backup did not require prior archives, it was safe to delete them. However, this has caused problems for some users in the past (because they needed the WAL for other purposes) and with the new adhoc and time-based retention features, it was decided that the archives should remain until the threshold was met. The archives will eventually be removed and if having them causes space issues, the expire command and the retention-archive can always be run and adjusted.
This functionality was embedded into TlsClient but that was starting to get unwieldy.
Add SocketClient to contain all socket-related client functionality.
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.
These commands (e.g. restore, archive-get) never used the compress options but allowed them to be passed on the command line. Now they will error when these options are passed on the command line. If these errors occur then remove the unused options.
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.
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.
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.
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.
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.
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.
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.
Amend commit 434cd832 to error when the db history in archive.info and backup.info do not match.
The Perl code would attempt to reconcile the history by matching on system id and version but we are not planning to migrate that code to C. It's possible that there are users with mismatches but if so they should have been getting errors from info for the last six months. It's easy enough to manually fix these files if there are any mismatches in the field.
Contributed by Cynthia Shang.
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 new implementation should behave exactly like the old Perl code with the exception of updated log messages.
Remove as much of the Perl code as possible without breaking other commands.
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.
The expect tests were originally a rough-and-ready type of unit test so monitoring changes in the expect log helped us detect changes in behavior.
Now the stanza code is heavily unit-tested so the detailed logs mainly cause churn and don't have any measurable benefit.
Reduce the log level to DETAIL to make the logs less verbose and volatile, yet still check user-facing log messages.
Expressions such as <REPO:ARCHIVE> require a stanza name in order to be resolved correctly. However, if the stanza name is passed to the remote then that remote will only work correctly for that one stanza.
Instead, resolved the expressions locally but still pass a relative path to the remote. That way, a storage path that is only configured on the remote does not need to be known locally.
This command was previously forked off from the archive-get command which required a bit of artificial option and log manipulation.
A separate command is easier to test and will work on platforms that don't have fork(), e.g. Windows.
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.
Apparently we never needed to run this function remotely.
It will be needed by the backup checksum delta feature, so implement it now.
Contributed by Cynthia Shang.
The info messages were spread around and logged differently based on the execution path and in some cases logged nothing at all.
Temporarily track the async server status with a flag so that info messages are not output in the async process. The async process will be refactored as a separate command to be exec'd in a future commit.
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.
Low-level functions only include stack trace in test builds while higher-level functions ship with stack trace built-in. Stack traces include all parameters passed to the function but production builds only create the parameter list when the log level is set high enough, i.e. debug or trace depending on the function.
The Perl process was exiting directly when called but that interfered with proper locking for the forked async process. Now Perl returns results to the C process which handles all errors, including signals.
Now only two types of locks can be taken: archive and backup. Most commands use one or the other but the stanza-* commands acquire both locks. This provides better protection than the old command-based locking scheme.
