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This is mostly a refactor, but a big change is the select() logic in fdRead.c has been replaced by ioReadReady().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.
