Multi-repository implementations for the archive-push, check, info, stanza-create, stanza-upgrade, and stanza-delete commands.
Multi-repo configuration is disabled so there should be no behavioral changes between these commands and their current single-repo implementations.
Multi-repo documentation and integration tests are still in the multi-repo development branch. All unit tests work as multi-repo since they are able to bypass the configuration restrictions.
Check that archive files exist in the main process instead of the local process. This means that the archive.info file only needs to be loaded once per execution rather than once per file to get.
Stop looking when a file is missing or in error. PostgreSQL will never request anything past the missing file so there is no point in getting them. This also reduces "unable to find" logging in the async process.
Cache results of storageList() when looking for multiple files to reduce storage I/O.
Look for all requested archive files in the archive-id where the first file is found. They may not all be there, but this reduces the number of list calls. If subsequent files are in another archive id they will be found on the next archive-get call.
If files other than backup.manifest.copy were left in a backup path by a prior resume then the next resume would skip the backup rather than removing it. Since the backup path still existed, it would be found during backup label generation and cause an error if it appeared to be later than the new backup label. This occurred if the skipped backup was full.
The error was only likely on object stores such as S3 because of the order of file deletion. Posix file systems delete from the bottom up because directories containing files cannot be deleted. Object stores do not have directories so files are deleted in whatever order they are provided by the list command. However, the issue can be reproduced on a Posix file system by manually deleting backup.manifest.copy from a resumable backup path.
Fix the issue by removing the resumable backup if it has no manifest files. Also add a new warning message for this condition.
Note that this issue could be resolved by running expire or a new full backup.
These options specify the number of local worker job retries and the retry interval after one immediate retry.
There is some value in allowing retries to be specified by the user but for the most part these options are for suppressing retries during testing, which can save a lot of time. The bug introduced in d1d25c7 and fixed in 8b86d5e also suggests it is better not to use retries in tests.
Remove the default delayed retries for archive-get/archive-push, leaving only the immediate retry. These commands are retried by PostgreSQL so it doesn't make sense to do too many retries internally.
These options are currently internal.
Building on 23f5712, limit option validity by role. This is mostly for options that weren't needed for certain roles but were harmless. However, the upcoming multi repository functionality requires the granularity implemented here.
The remote role benefits since host options can automatically excluded when building the options. Also, many options that are only required for the default role (e.g. repo-retention-full) no longer need to be passed in tests for other roles.
The pack type is an architecture-independent format for serializing data compactly, inspired by ProtocolBuffers and Avro.
Also add ioReadSmall(), which is optimized for small binary reads, similar to ioReadLineParam().
The C code does not use doubles to represent seconds like the Perl code did so time can be represented as an integer which reduces the number of data types that config has to understand.
Also remove Variant doubles since they are no longer used.
Note that not all double code was removed since we still need to display times to the user in seconds and it is possible for the times to be fractional. In the future this will likely be simplified by storing the original user input and using that value when the time needs to be displayed.
Bug Fixes:
* Allow [, #, and space as the first character in database names. (Reviewed by Stefan Fercot, Cynthia Shang. Reported by Jefferson Alexandre.)
* Create standby.signal only on PostgreSQL 12 when restore type is standby. (Fixed by Stefan Fercot. Reviewed by David Steele. Reported by Keith Fiske.)
Features:
* Expire history files. (Contributed by Stefan Fercot. Reviewed by David Steele.)
* Report page checksum errors in info command text output. (Contributed by Stefan Fercot. Reviewed by Cynthia Shang.)
* Add repo-azure-endpoint option. (Reviewed by Cynthia Shang, Brian Peterson. Suggested by Brian Peterson.)
* Add pg-database option. (Reviewed by Cynthia Shang.)
Improvements:
* Improve info command output when a stanza is specified but missing. (Contributed by Stefan Fercot. Reviewed by Cynthia Shang, David Steele. Suggested by uspen.)
* Improve performance of large file lists in backup/restore commands. (Reviewed by Cynthia Shang, Oscar.)
* Add retries to PostgreSQL sleep when starting a backup. (Reviewed by Cynthia Shang. Suggested by Vitaliy Kukharik.)
Documentation Improvements:
* Replace RHEL/CentOS 6 documentation with RHEL/CentOS 8.
Update RHEL/CentOS 7 to cover the versions that were previously covered by RHEL/CentOS 6.
Since RHEL/CentOS 7/8 work the same update the documentation logic and labels to reflect this compatibility.
Inaccuracies in sleep time or clock skew might make a single sleep insufficient to reach the next second.
Add a few retries to make the process more reliable but still avoid an infinite loop if something is seriously wrong.
Refactor the code to allow a dynamic number of indexes for indexed options, e.g. pg-path. Our reliance on getopt_long() still limits the number of indexes we can have per group, but once this limitation is removed the rest of the code should be happy with dynamic numbers of indexes (with a reasonable maximum).
Add an option to set a default in each group. This was previously handled by the host-id option but now there is a specific option for each group, pg and repo. These remain internal until they can be fully tested with multi-repo support. They are fully tested for internal usage.
Remove the ConfigDefineOption enum and use the ConfigOption enum instead. They are now equal since the indexed options (e.g. cfgOptRepoHost2) have been removed from ConfigOption.
Remove the config/config test module and add required tests to the config/parse test module. Parsing is now the only way to load a config so this removes some redundancy.
Split new internal config structures and functions into a new header file, config.intern.h. More functions will need to be moved over from config.h but that will need to be done in a future commit to reduce churn.
Add repoIdx to repoIsLocal() and storageRepo*(). Multi-repository support requires that repo locality and storage be accessible by index. This allows, for example, multiple repos to be iterated in a loop. This could be done in a separate commit but doesn't seem worth it since the code is related.
Remove the type parameter from storageRepoGet(). This parameter existed solely to provide coverage for the case where the storage type was invalid. A better pattern is to check that the type is S3 once all other types have been ruled out.
Improve locking on remote processes by introducing an exec-id that is unique to the main process and passed to all remote processes. This allows the remote processes to determine if a lock is held by a remote from the same main process. If so, the lock is allowed.
The exec-id is also useful for associating remote logs with main logs for debugging purposes.
When restore type standby is provided, the recovery.signal isn't needed and may lead to some confusion (see #1236).
Lately, when using pg_basebackup --write-recovery-conf, only the standby.signal file is created. This change would then align with that behaviour.
Return a path missing error when a stanza is specified for the info command but the stanza does not exist in the repository.
Previously [] was returned, which is still the case if no stanza is specified and the repository does not exist.
lstRemoveIdx(list, 0) resulted in the entire list being moved down to the first position which could take a long time for big lists. This is a common pattern in backup/restore when processing file queues.
Instead simply move the list pointer up when first item is removed. Then on insert check if there is space at the beginning when there is no longer space at the end and do the move then. This way if a list is built and then drained without any new inserts then no move is required.
There were a number of places in the code where "hostId" was used, but hostId is just the option group index + 1 so this led to a lot of +1 and -1 to convert the id to an index and vice versa.
Instead just use the zero based index wherever possible. This is pretty much everywhere except when the host-id option is read or set, or where a message is being formatted for the user.
Also fix a bug in protocolRemoteParam() where remotes spawned from the main process could get process ids that were not 0. Only the locals should spawn remotes with process id > 0. This seems to have been harmless since the process id is only a label, but it could be confusing when debugging.
iniLoad() was trimming lines which meant that a leading space would not pass checksum validation when a manifest was reloaded. Remove the trims since files we write should never contain extraneous spaces. This further diverges the format for the functions that read conf files (e.g. pgbackrest.conf) and those that read info (e.g. manifest) files.
While we are at it also allow [ and # as initial characters. # was reserved for comments but we never put comments into info files. [ denotes a section but we can get around this by never allowing arrays as values in info files, so if a line ends in ] it must be a section. This is currently the case but enforce it by adding an assert to info/info.c.
WAL timeline history files were not being expired because they were small and generally not very plentiful.
However, in some cases large numbers of history files may be generated so it makes sense to remove useless history files to keep things tidy.
The history file for the oldest retained timeline is kept for debugging purposes even though it is not used for recovery.
Instead of using memmove() to manage the internal output buffer for every small read, track the current buffer position and only move data when the small read cannot be satisfied and more data is needed.
Group related options together so operations (e.g. valid, test, index total) can be performed on all options in the group.
Previously, options at the top of the hierarchy of the related options were used to do these tests. This was prone to error as option relationships changed and it was not always clear which option (or options) should be used.
Bug Fixes:
* Error with hints when backup user cannot read pg_settings. (Reviewed by Stefan Fercot, Cynthia Shang. Reported by Mohamed Insaf K.)
Features:
* PostgreSQL 13 support. (Reviewed by Cynthia Shang.)
Improvements:
* Improve PostgreSQL version identification. (Reviewed by Cynthia Shang, Stephen Frost.)
* Improve working directory error message. (Reviewed by Stefan Fercot.)
* Add hint about starting the stanza when WAL segment not found. (Contributed by David Christensen. Reviewed by David Steele.)
* Add hint for protocol version mismatch. (Reviewed by Cynthia Shang. Suggested by loop-evgeny.)
Documentation Improvements:
* Add note that pgBackRest versions must match when running remotely. (Reviewed by Cynthia Shang. Suggested by loop-evgeny.)
* Move info command text to the reference and link to user guide. (Reviewed by Cynthia Shang. Suggested by Christophe Courtois.)
* Update yum repository path for CentOS/RHEL user guide. (Contributed by Heath Lord. Reviewed by David Steele.)
This means the same text will appear in both places, which should make it easier to find.
Also update the link code to allow both page and section to be specified rather than only one or the other.
Update the documentation to explicitly state that versions must match across hosts when running remotely.
Add a hint to the protocol version mismatch error to help the user identify the problem.
Add older PostgreSQL versions to the u18 container that were not available before.
This also updates all minor versions for prior versions of PostgreSQL.
Scan the WAL archive for missing or invalid files and build up ranges of WAL that will be used to verify backup integrity. A number of errors and warnings are currently emitted but they should not be considered authoritative (yet).
The command is incomplete so is marked internal.
Previously, catalog versions were fixed for all versions which made maintaining the catalog versions during PostgreSQL beta and release candidate cycles very painful. A version of pgBackRest which was functionally compatible was rendered useless by a catalog version bump in PostgreSQL.
Instead use only the control version to identify a PostgreSQL version when possible. Some older versions require a catalog version to positively identify a PostgreSQL version, so include them when required.
Since the catalog number is required to work with tablespaces it will need to be stored. There's already a copy of it in backup.info so use that (even though we have been ignoring it in the C versions).
This condition used to give a not-very-clear error which we have been intending to improve. But in the meantime the changes in fbff299 resulted in a segfault for this condition instead because the data_directory was assumed to be non-NULL.
Fix this by explicitly throwing an error with hints when any row in pg_settings cannot be selected.
This file is created by pg_basebackup so might be in the data directory if the cluster was restored from a pg_basebackup backup. Also exclude backup_manifest.tmp since it is possible to find that in the backup directory.
Improve the wording of the error message and add a hint to make it clearer what is wrong and how the user can fix it.
Also change the assert to a regular error since this is not an internal error.
If a stop command has been issued the check command fails due to archiving timing out.
Provide a hint to document this situation and point the user in the proper direction.
If the callback never returned any jobs then protocolParallelDone() would never be true. The reason is that the done state was being set in protocolParallelResult(), which never gets called if there are no results.
Calling protocolParallelResult() doesn't make much sense in this case so instead move the done logic to protocolParallelDone().
For current usage of ProtocolParallel we ensure there are jobs before processing so this is not a live issue, but the new behavior is required for future development.
Bug Fixes:
* Suppress errors when closing local/remote processes. Since the command has completed it is counterproductive to throw an error but still warn to indicate that something unusual happened. (Reviewed by Cynthia Shang. Reported by argdenis.)
* Fix issue with = character in file or database names. (Reviewed by Bastian Wegge, Cynthia Shang. Reported by Brad Nicholson, Bastian Wegge.)
Features:
* Automatically retrieve temporary S3 credentials on AWS instances. (Contributed by David Steele, Stephen Frost. Reviewed by Cynthia Shang, David Youatt, Aleš Zelený, Jeanette Bromage.)
* Add archive-mode option to disable archiving on restore. (Reviewed by Stephen Frost. Suggested by Stephen Frost.)
Improvements:
* PostgreSQL 13 beta3 support. Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
* Asynchronous list/remove for S3/Azure storage. (Reviewed by Cynthia Shang, Stephen Frost.)
* Improve memory usage of unlogged relation detection in manifest build. (Reviewed by Cynthia Shang, Stephen Frost, Brad Nicholson, Oscar. Suggested by Oscar, Brad Nicholson.)
* Proactively close file descriptors after forking async process. (Reviewed by Stephen Frost, Cynthia Shang.)
* Delay backup remote connection close until after archive check. (Contributed by Floris van Nee. Reviewed by David Steele.)
* Improve detailed error output. (Reviewed by Cynthia Shang.)
* Improve TLS error reporting. (Reviewed by Cynthia Shang, Stephen Frost.)
Documentation Bug Fixes:
* Add none to compress-type option reference and fix example. (Reported by Ugo Bellavance, Don Seiler.)
* Add missing azure type in repo-type option reference. (Fixed by Don Seiler. Reviewed by David Steele.)
* Fix typo in repo-cipher-type option reference. (Fixed by Don Seiler. Reviewed by David Steele.)
Documentation Improvements:
* Clarify that expire must be run regularly when expire-auto is disabled. (Reviewed by Douglas J Hunley. Suggested by Douglas J Hunley.)
When restoring a cluster that will be promoted but is not intended to be the new primary, it is important to disable archiving to avoid polluting the repository with useless WAL. This option makes disabling archiving a bit easier.
Automatically retrieve the role and temporary credentials for S3 when the AWS instance is associated with an IAM role. Credentials are automatically updated when they are <= 5 minutes from expiring.
Basic configuration is to set repo1-s3-key-type=auto. repo1-s3-role can be used to set a specific role, otherwise it will be retrieved automatically.
Add more info (command, version, options) to asserts, and errors when debug logging is enabled. This won't cover all cases but might mean we get more info in some circumstances.
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.
Improve the performance of list/delete operations by using async requests.
It's questionable whether this will have any impact on Azure deletes since they are sent one at a time with little work done in between, but it doesn't hurt to try.
HTTP/1.0 connections are closed by default after a single response. Other than that, treat 1.0 the same as 1.1.
HTTP/1.0 allows different date formats that we can't parse but for now, at least, we don't need any date headers from 1.0 requests.
Following up on 111d33c, implement the new interfaces for socket client/session. Now HTTP objects can be used over TLS or plain sockets.
This required adding ioSessionFd() and ioSessionRole() to provide the functionality of sckSessionFd() and sckSessionType(). sckClientHost() and sckClientPort don't make sense in a generic interface so they were replaced with ioSessionName().
Only close the remote connection after verifying that the WAL files have been received. This is necessary if the archive_command on the PostgreSQL host is conditional, i.e. archiving only happens while a backup lock is held, to ensure all WAL segments are archived.
Move sckSessionReadyRead()/Write() into the IoRead/IoWrite interfaces. This is a more logical place for them and the alternative would be to add them to the IoSession interface, which does not seem like a good idea.
This is mostly a refactor, but a big change is the select() logic in fdRead.c has been replaced by ioReadReady(). This was duplicated code that was being used by our protocol but not TLS. Since we have not had any problems with requiring poll() in the field this seems like a good time to remove our dependence on select().
Also, IoFdWrite now requires a timeout so update where required, mostly in the tests.
These interfaces allow the HttpClient and HttpSession objects to work with protocols other than TLS, .e.g. plain sockets. This is necessary to allow standard HTTP -- right now only HTTPS is allowed, i.e. HTTP over TLS.
For now only TlsClient and TlsSession have been converted to the new interfaces. SocketClient and SocketSession will also need to be converted but first sckSessionReadyRead() and sckSessionReadyWrite() need to be moved into the IoRead and IoWrite interfaces, since they are not a good fit for IoSession.
Before 9f2d647 TLS errors included additional details in at least some cases. After 9f2d647 a connection to an HTTP server threw `TLS error [1]` instead of `unable to negotiate TLS connection: [336031996] unknown protocol`.
Bring back the detailed messages to make debugging TLS errors easier. Since the error routine is now generic the `unable to negotiate TLS connection context` is not available so the error looks like `TLS error [1:336031996] unknown protocol`.
PostgreSQL may be using most of the available file descriptors when it executes the the archive-get/archive-push commands (especially archive-get). This can lead to problems depending on how many file descriptors are needed for parallelism in the async process.
Proactively free file descriptors between 3 and 1023 to help ensure there are enough available for reasonable values of process-max, i.e. <= 300.
This loop was using a lot of memory without freeing it at intervals.
Rewrite to use char arrays when possible to reduce memory that needs to be allocated and freed.
The fix for = characters in info files (039d314) added JSON validation but discarded the resulting Variant which means the JSON is being parsed twice. This nearly doubles the time to load a manifest since a lot of complex JSON is involved.
Time to load a million file manifest:
Before 039d314: 7.8s
039d314: 15.5s
This patch: 7.5s
To fix this regression return the Variant in the callback so the caller does not have to parse it again. The new code appears slightly more efficient overall, probably because there are fewer operations against Strings.
The manifest uses the = character as the key/value separator so = characters in the key cause parsing errors and lead to an error or segfault.
Since the value must be valid JSON we can keep checking the value on the right side of the = and stop building the key when the value is valid. It's a bit hackish but it does seem to do the job without breaking the manifest format.
Unsurprisingly this makes parsing about 50% slower but it's still more than fast enough. Parsing 10 million key/values takes about 6.5s for the old code and 10s for the new code. Since the value is used as JSON downstream we can reclaim most of this time by just passing the JSON value rather than making the callback reparse it. We'll save that for another commit, though.
Since the command has completed it is counterproductive to throw an error but still warn to indicate that something unusual happened.
Also fix the related issue that the local processes were not being shut down when they completed, which meant that they might timeout before being closed when pgbackrest terminated.
Bug Fixes:
* Fix restore --force acting like --force --delta. This caused restore to replace files based on timestamp and size rather than overwriting, which meant some files that should have been updated were left unchanged. Normal restore and restore --delta were not affected by this issue. (Reviewed by Cynthia Shang.)
Features:
* Azure support for repository storage. (Reviewed by Cynthia Shang, Don Seiler.)
* Add expire-auto option. This allows automatic expiration after a successful backup to be disabled. (Contributed by Stefan Fercot. Reviewed by Cynthia Shang, David Steele.)
Improvements:
* Asynchronous S3 multipart upload. (Reviewed by Stephen Frost.)
* Automatic retry for backup, restore, archive-get, and archive-push. (Reviewed by Cynthia Shang.)
* Disable query parallelism in PostgreSQL sessions used for backup control. (Reviewed by Stefan Fercot.)
* PostgreSQL 13 beta2 support. Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
* Improve handling of invalid HTTP response status. (Reviewed by Cynthia Shang.)
* Improve error when pg1-path option missing for archive-get command. (Reviewed by Cynthia Shang.)
* Add hint when checksum delta is enabled after a timeline switch. (Reviewed by Matt Bunter, Cynthia Shang.)
* Use PostgreSQL instead of postmaster where appropriate. (Reviewed by Cynthia Shang.)
Documentation Bug Fixes:
* Fix incorrect example for repo-retention-full-type option. (Reported by Höseyin Sönmez.)
* Remove internal commands from HTML and man command references. (Reported by Cynthia Shang.)
Documentation Improvements:
* Update PostgreSQL versions used to build user guides. Also add version ranges to indicate that a user guide is accurate for a range of PostgreSQL versions even if it was built for a specific version. (Reviewed by Stephen Frost.)
* Update FAQ for expiring a specific backup set. (Contributed by Cynthia Shang. Reviewed by David Steele.)
* Update FAQ to clarify default PITR behavior. (Contributed by Cynthia Shang. Reviewed by David Steele.)
Remove all check and stanza-* tests except for the ones that are intended to succeed. The successful tests show that the queries run with expected results against each version of PG which should also validate queries for the failure tests in the unit tests.
Also remove the tests for --no-online backups since they don't require a database and are well tested in the unit tests.
The prior code was only able to use the main passphrase automatically and expected sub passphrases to be specified for each operation. This was fine for testing but hardly sufficient for a user-facing feature.
Update the code to determine which passphrase to use for any file in the repository and error when an invalid file or location is selected.
The repo-get command is still internal for now, but with this improvement it should be ready to be made public.
If a local command, e.g. backupFile(), fails it will stop the entire process. Instead, retry local commands to deal with transient errors.
Remove special logic in the S3 storage driver to retry RequestTimeTooSkewed errors since this is now handled by the general retry mechanism in the places where it is most likely to happen, i.e. file read/write. Also, this error should have been entirely eliminated by the asynchronous TLS implementation.
A shared access signature (SAS) provides granular, delegated access to resources in a storage account. This is often preferable to using a shared key which provides more access and is a greater security risk if compromised.
This caused restore to replace files based on timestamp and size rather than overwriting, which meant some files that should have been updated were left unchanged. Normal restore and restore --delta were not affected by this issue.
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.
There don't appear to be any behavioral changes since PostgreSQL 12 and all the tests pass.
Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
There is no need to have parallelism enabled in a backup control session. In particular, 9.6 marks pg_stop_backup() as parallel-safe but an error will be thrown if pg_stop_backup() is run in a worker.
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).
strPtr() is called more than any other function and during profiling (with or without optimization) it can end up using a disproportionate amount of the total runtime. Even though it is fast, the profiler has a minimum resolution for each function call so strPtr() will often end up towards the top of the list even though the real runtime is quite small.
Instead, inline strPtr() and indicate to gcc that it should be inlined even for non-optimized builds, since that's how profiles are usually generated.
To make strPtr() smaller require "this" to be non-NULL and add another function, strPtrNull(), to deal with the few cases where we need NULL handling.
As a bonus this makes the executable about 1% smaller even when compared to a prior optimized build which would inline some percentage of strPtr() calls.
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.
Expressions only worked at the first level of recursion because the expression was also being applied to paths so the path had to match the filter in order to recurse.
This is not considered a bug since it does not affect any existing code paths, but it is required for the general-purpose repo-ls command.
A truncated HTTP response status could lead to an an unfriendly error message, which would be retried, but could be confusing if the error was persistent and required debugging.
Improve the error handling overall to catch more error cases explicitly and respond better to edge cases.
Also update the terminology in comments to align with the RFC. Variable and function names were not changed because a refactor is intended for HTTP response and it doesn't seem worth the additional code churn.
Bug Fixes:
* Fix issue checking if file links are contained in path links. (Reviewed by Cynthia Shang. Reported by Christophe Cavallié.)
* Allow pg-path1 to be optional for synchronous archive-push. (Reviewed by Cynthia Shang. Reported by Jerome Peng.)
* The expire command now checks if a stop file is present. (Fixed by Cynthia Shang. Reviewed by David Steele.)
* Handle missing reason phrase in HTTP response. (Reviewed by Cynthia Shang. Reported by Tenuun.)
* Increase buffer size for lz4 compression flush. (Reviewed by Cynthia Shang. Reported by Eric Radman.)
* Ignore pg-host* and repo-host* options for the remote command. (Reviewed by Cynthia Shang. Reported by Pavel Suderevsky.)
* Fix possibly missing pg1-* options for the remote command. (Reviewed by Cynthia Shang. Reported by Andrew L'Ecuyer.)
Features:
* Time-based retention for full backups. The --repo-retention-full-type option allows retention of full backups based on a time period, specified in days. (Contributed by Cynthia Shang, Pierre Ducroquet. Reviewed by David Steele.)
* Ad hoc backup expiration. Allow the user to remove a specified backup regardless of retention settings. (Contributed by Cynthia Shang. Reviewed by David Steele.)
* Zstandard compression support. Note that setting compress-type=zst will make new backups and archive incompatible (unrestorable) with prior versions of pgBackRest. (Reviewed by Cynthia Shang.)
* bzip2 compression support. Note that setting compress-type=bz2 will make new backups and archive incompatible (unrestorable) with prior versions of pgBackRest. (Contributed by Stephen Frost. Reviewed by David Steele, Cynthia Shang.)
* Add backup/expire running status to the info command. (Contributed by Stefan Fercot. Reviewed by David Steele.)
Improvements:
* Expire WAL archive only when repo-retention-archive threshold is met. WAL prior to the first full backup was previously expired after the first full backup. Now it is preserved according to retention settings. (Contributed by Cynthia Shang. Reviewed by David Steele.)
* Add local MD5 implementation so S3 works when FIPS is enabled. (Reviewed by Cynthia Shang, Stephen Frost. Suggested by Brian Almeida, John Kelley.)
* PostgreSQL 13 beta1 support. Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace. (Reviewed by Cynthia Shang.)
* Reduce buffer-size default to 1MiB. (Reviewed by Stephen Frost.)
* Throw user-friendly error if expire is not run on repository host. (Contributed by Cynthia Shang. Reviewed by David Steele.)
The purpose of the remote command is to get access to local resources, so a remote should never start another remote. However, this could happen if there were host settings on the remote host, which ended badly with lock errors, loops, etc.
Add pg-local and repo-local options to indicate that the resource is local even if there are host settings.
Note that for the time being these options are internal and not intended for general usage. However, this is likely the direction needed to allow for more symmetric and manageable configurations.
Some pg1-* options are required by the remote so if they are not provided in the remote's configuration file then it may cause a configuration error, depending on the operation. This currently only applies to the pg1-path option.
This is still an issue for repo-* options but the same solution cannot be applied because some repo-* options are secure and cannot be passed on the command-line.
There don't appear to be any behavioral changes since PostgreSQL 12 and all the tests pass.
Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
S3 requires the Content-MD5 header for many requests but MD5 is not available via OpenSSL when FIPS is enabled because it is considered to be insecure.
Even though our usage does not present any security risks a local M5 implementation is required to circumvent the over-broad FIPS restriction.
Vendorize the MD5 implementation found at https://openwall.info/wiki/people/solar/software/public-domain-source-code/md5 and add full coverage for the module in the common/crypto unit tests.
