"gz" was used as the extension but "gzip" was generally used for function and type naming.
With a new compression format on the way, it makes sense to standardize on a single abbreviation to represent a compression format in the code. Since the extension is standard and we must use it, also use the extension for all naming.
The prior code used TRY...CATCH blocks to cleanup mem contexts when an error occurred. This included freeing new mem contexts that were still being initialized when the error occurred and ensuring that the prior memory context was restored.
This worked fine in production but it involved a lot of setjmp()/longjmp() calls that resulted in longer compilation times and sluggish performance under valgrind, profiling, and coverage testing.
Instead maintain a stack of new contexts and context switches that can be used to do cleanup after an error. Normally, the stack is not used for this purpose and pushing/popping is a cheap operation. In the prior implementation most of the TRY...CATCH logic needed to be run even on success.
One bonus is that the binary is about 8% smaller after this change. Another benefit is that new contexts *must* be explicitly freed/discarded or an error will occur. See info/manifest.c for an example of where this is useful outside the standard macros.
If PostgreSQL crashes it can leave behind a pg_internal.init temp file with the pid as the extension, as discussed in https://www.postgresql.org/message-id/flat/20200131045352.GB2631%40paquier.xyz#7700b9481ef5b0dd5f09cc410b4750f6. On restart this file is not cleaned up so it can persist for the lifetime of the cluster or until another process with the same id happens to write pg_internal.init.
This is arguably a bug in PostgreSQL, but in any case it makes sense not to backup this file.
This error was lost during the migration to C. The error that occurred instead (generally an SSH auth error) was hard to debug.
Restore the original behavior by throwing an error immediately if pg1-host is configured for any of these commands. reset-pg1-host can be used to suppress the error when required.
The main improvement is a double-fork to prevent zombie processes if the parent process exits after the (child) async process. This is a real possibility since the parent process sticks around to monitor the results of the async process.
In the first fork, ignore SIGCHLD in the very unlikely case that the async process exits before the first fork. This is probably only possible if the async process exits immediately, perhaps due to a chdir() failure. Set SIGCHLD back to default in the async process so waitpid() will work as expected.
Also update the comment on chdir() to more accurately reflect what is happening.
Finally, add a test in certain debug builds to ensure the first fork exits very quickly. This only works when valgrind is not in use because valgrind makes forking so slow that it is hard to tell if the async process performed work or not (in the case that the second fork goes missing and the async process is a direct child).
In this case the resumable backup should be ignored, but the C code was not able to load the partial manifest written by Perl since the format differs slightly. Add validations to catch this case and continue gracefully.
2a06df93 removed the error file so an old error would not be reported before the async process had a chance to try again. However, if the async process was already running this might lead to a timeout error before reporting the correct error.
Instead, remove the error files once we know that the async process will start, i.e. after the archive lock has been acquired.
This effectively reverts 2a06df93.
Generally, the content-size or content-encoding headers will be used to specify how much content should be expected.
There is a special case where the server sends 'Connection:close' without the content headers and the content may be read up until eof.
This appears to be an atypical usage but it is required by the specification.
Auto-selection is performed only when --set is not specified. If a backup set for the given target time cannot not be found, the latest (default) backup set will be used.
Currently a limited number of date formats are recognized and timezone names are not allowed, only timezone offsets.
Add tzPartsValid() and tzOffsetSecond() to calculate timezone offsets from user provided values.
Update epochFromParts() to accept a timezone offset in seconds.
The test that checks for no output from the server was leaving a connection open which valgrind was complaining about.
Wait on the server long enough to cause the error on the client then close the connection to free the memory.
Validate that checksums exist for zero size files. This means that the checksums for zero size files are explicitly set by backup even though they'll always be the same. Also validate that zero length files have the correct checksum.
Validate that repo size is > 0 if size is > 0. No matter what compression type is used a non-zero amount of data cannot be stored in zero bytes.
This is a modest start but it addresses the specific issue that was caused by the bug fixed in 45ec694a. This validation will produce an immediate error rather than erroring out partway through the restore.
More validations are planned but this is the most important one and seems safest for this release.
If a file was removed by PostgreSQL during the backup (or was missing from the standby) then the next file might not be copied and updated in the manifest. If this happened then the backup would error when restored.
The issue was that removing files from the manifest invalidated the pointers stored in the processing queues. When a file was removed, all the pointers shifted to the next file in the list, causing a file to be unprocessed. Since the unprocessed file was still in the manifest it would be saved with no checksum, causing a failure on restore.
When process-max was > 1 then the bug would often not express since the file had already been pulled from the queue and updates to the manifest are done by name rather than by pointer.
pkg-config is a generic way to get build options rather than relying on a package-specific utility.
XML2_CONFIG can be used to override this utility for systems that do not ship pkg-config.
Previously memNew() used memset() to initialize all struct members to 0, NULL, false, etc. While this appears to work in practice, it is a violation of the C specification. For instance, NULL == 0 must be true but neither NULL nor 0 must be represented with all zero bits.
Instead use designated initializers to initialize structs. These guarantee that struct members will be properly initialized even if they are not specified in the initializer. Note that due to a quirk in the C99 specification at least one member must be explicitly initialized even if it needs to be the default value.
Since pre-zeroed memory is no longer required, adjust memAllocInternal()/memReallocInternal() to return raw memory and update dependent functions accordingly. All instances of memset() have been removed except in debug/test code where needed.
Add memMewPtrArray() to allocate an array of pointers and automatically set all pointers to NULL.
Rename memGrowRaw() to the more logical memResize().
The timeline is required to verify WAL segments in the archive after a backup. The conversion was performed base 10 instead of 16, which led to errors when the timeline was ≥ 0xA.
This macro block encapsulates the common pattern of switching to the prior (formerly called old) mem context to return results from a function.
Also rename MEM_CONTEXT_OLD() to memContextPrior(). This violates our convention of macros being in all caps but memContextPrior() will become a function very soon so this will reduce churn.
A few places were using just memContextNew(), probably because they did not immediately need to create anything in the new context, but it's better if we use the same pattern everywhere, even if it results in a few extra mem context switches.
Bug Fixes:
* Fix options being ignored by asynchronous commands. The asynchronous archive-get/archive-push processes were not loading options configured in command configuration sections, e.g. [global:archive-get]. (Reviewed by Cynthia Shang. Reported by Urs Kramer.)
* Fix handling of \ in filenames. \ was not being properly escaped when calculating the manifest checksum which prevented the manifest from loading. Since instances of \ in cluster filenames should be rare to nonexistent this does not seem likely to be a serious problem in the field.
Features:
* pgBackRest is now pure C.
* Add pg-user option. Specifies the database user name when connecting to PostgreSQL. If not specified pgBackRest will connect with the local OS user or PGUSER, which was the previous behavior. (Contributed by Mike Palmiotto.)
* Allow path-style URIs in S3 driver.
Improvements:
* The backup command is implemented entirely in C. (Reviewed by Cynthia Shang.)
The local, remote, archive-get-async, and archive-push-async commands were used to run functionality that was not directly available to the user. Unfortunately that meant they would not pick up options from the command that the user expected, e.g. backup, archive-get, etc.
Remove the internal commands and add roles which allow pgBackRest to determine what functionality is required without implementing special commands. This way the options are loaded from the expected command section.
Since remote is no longer a specific command with its own options, more manipulation is required when calling remote. This might be something we can improve in the config system but it may be worth leaving as is because it is a one-off, for now at least.
Although path-style URIs have been deprecated by AWS, they may still be used with products like Minio because no additional DNS configuration is required.
Path-style URIs must be explicitly enabled since it is not clear how they can be auto-detected reliably. More importantly, faulty detection could cause regressions in current installations.
Time is supported in all drivers with the update to S3 at 61538f93, so it is now possible to add time to the ls command and have it work on all repo types.
Parameter lists that are passed directly to exec*() do not need quoting when spaces are present. Worse, the quotes will not be stripped and the option value will be garbled.
Unfortunately this still does not fix all issues with quoting since we don't know how it might need to be escaped to work with SSH command configuration. The answer seems to be to pass the options in the protocol layer but that's beyond the scope of this commit.
This option was overloaded on the general type option but it makes sense to split this out since the meaning is pretty different.
Rename the values to conform to current standards, i.e. pg and repo, now that the Perl code won't care anymore.
Previously dates were not being filled by these functions which was fine since dates were not used.
We plan to use dates for the ls command plus it makes sense for the driver to be complete since it will be used as an example.
These are similar to what mktime() and strptime() do but they ignore the local system timezone which saves having to munge the TZ env variable to do time conversions.
This macro was created before the String object existed so subsequent usage with String always included a lot of strPtr() wrapping.
TEST_RESULT_STR_Z() had already been introduced but a wholesale replacement of TEST_RESULT_STR() was not done since the priority was on the C migration.
Update all calls to (old) TEST_RESULT_STR() with one of the following variants: (new) TEST_RESULT_STR(), TEST_RESULT_STR_Z(), TEST_RESULT_Z(), TEST_RESULT_Z_STR().
Specifies the database user name when connecting to PostgreSQL.
If not specified pgBackRest will connect with the local OS user or PGUSER, which was the previous behavior.
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.
