Bug Fixes:
* Remove empty subexpression from manifest regular expression. MacOS was not happy about this though other platforms seemed to work fine. (Fixed by David Raftis.)
Improvements:
* Non-blocking TLS implementation. (Reviewed by Slava Moudry, Cynthia Shang, Stephen Frost.)
* Only limit backup copy size for WAL-logged files. The prior behavior could possibly lead to postgresql.conf or postgresql.auto.conf being truncated in the backup. (Reviewed by Cynthia Shang.)
* TCP keep-alive options are configurable. (Suggested by Marc Cousin.)
* Add io-timeout option.
Timeout used for connections and read/write operations.
Note that the entire read/write operation does not need to complete within this timeout but some progress must be made, even if it is only a single byte.
The prior blocking implementation seemed to be prone to locking up on some (especially recent) kernel versions. Since we were unable to reproduce the issue in a development environment we can only speculate as to the cause, but there is a good chance that blocking sockets were the issue or contributed to the issue.
So move to a non-blocking implementation to hopefully clear up these issues. Testing in production environments that were prone to locking shows that the approach is promising and at the very least not a regression.
The main differences from the blocking version are the non-blocking connect() implementation and handling of WANT_READ/WANT_WRITE retries for all SSL*() functions.
Timeouts in the tests needed to be increased because socket connect() and TLS SSL_connect() were not included in the timeout before. The tests don't run any slower, though. In fact, all platforms but Ubuntu 12.04 worked fine with the shorter timeouts.
select() is a bit old-fashioned and cumbersome to use. Since the select() code needed to be modified to handle write ready this seems like a good time to upgrade to poll().
poll() has been around for a long time so there doesn't seem to be any need to provide a fallback to select().
Also change the error on timeout from FileReadError to ProtocolError. This works better for read vs. write and failure to poll() is indicative of a protocol error or unexpected EOF.
The prior behavior introduced in dcddf3a5 could possibly lead to postgresql.conf or postgresql.auto.conf being truncated in the backup since they are copied via tmp files and could change size during the backup.
In general it seems safer to limit this feature to WAL-logged files which will be reconstructed during recovery.
A session looks much the same whether it is initiated from the client or the server, so use the session objects to implement the TLS, HTTP, and S3 test servers.
For TLS, at least, there are some differences between client and server sessions so add a client/server type to SocketSession to determine how the session was initiated.
Aside from reducing code duplication, the main advantage is that the test server will now timeout rather than hanging indefinitely when less input that expected is received.
Previously an error was only thrown when errno was set but in practice this is usually not the case. This may have something to do with getting errno late but attempts to get it earlier have not been successful. It appears that errno usually gets cleared and spot research seems to indicate that other users have similar issues.
An error at this point indicates unexpected EOF so it seems better to just throw an error all the time and be consistent.
To test this properly our test server needs to call SSL_shutdown() except when the client expects this error.
This abstraction allows the session code to be shared between the TLS client and (upcoming) server code.
Session management is no longer implemented in TlsClient so the HttpClient was updated to free and create sessions as needed. No test changes were required for HttpClient so the functionality should be unchanged.
Mechanical changes to the TLS tests were required to use TlsSession where appropriate rather than TlsClient. There should be no change in functionality other than how sessions are managed, i.e. using tlsClientOpen()/tlsSessionFree() rather than just tlsClientOpen().
The errorInternalThrowSys*() functions were marked as returning during coverage testing even when they had no possibility to return, i.e. the error parameter was set to constant true. This meant the compiler would treat the functions as returning even when they would not.
Instead create completely separate functions for coverage to use for THROW_ON_SYS_ERROR*() that can return and leave the regular functions marked __noreturn__.
This abstraction allows the session code to be shared between the socket client and (upcoming) server code. There should no difference in how the code works -- only the organization has changed. Note that no changes to the tests were required.
This same abstraction will be required for TlsClient but that will be done in a separate commit because it requires test changes.
When the Vagrant file was updated to use pgbackrest/ vs /backrest/ as the location for executing tests and building the documentation, parts of the contributing.xml (and hence the CONTRIBUTING.md) were not updated since some parts of the document are not actually executed when the CONTRIBUTING.md is built from contributing.xml: those parts that are executed were updated but those parts that are not executed were not.
This commit fixes the contributing.xml issue but also removes test/README.md as its contents were out of date and redundant given that they are covered in CONTRIBUTING.md.
The storage driver requires two list functions to be implemented, list and infoList. But the former is a subset of the latter so implementing both in every driver is wasteful. The reason both exist is that in Posix it is cheaper to get a list of names than it is to stat files to get size, time, etc. In S3 these operations are equivalent.
Introduce storageInfoLevelType to determine the amount of information required by the caller. That way Posix can work efficiently and all drivers can return only the data required which saves some bandwidth. The storageList() and storageInfoList() functions remain in the storage interface since they are useful -- the only change is simplifying the drivers with no external impact.
Note that since list() accepted an expression infoList() must now do so. Checking the expression is optional for the driver but can be used to limit results or save IO costs.
Similarly, exists() and pathExists() are just specialized forms of info() so adapt them to call info() instead.
This has been the policy for some time but due to migration pressure only new functions and refactors have been following this rule. Now it seems sensible to make a clean sweep and move all the comments that have not been moved already (i.e. most of them).
Only obvious typos and gross inaccuracies in the comments have been fixed. For this most part this was a copy and paste operation.
Useless comments, e.g. "New object", were not copied. Even so, there are surely many deficient comments left.
Some rearranging was done where needed and functions were placed in the proper sections, e.g. "Constructors", "Functions", etc.
A few function prototypes were found that not longer had an implementation. These were removed, but there may be more.
The coding document has been updated to reflect this policy, which is not new but has never been documented.
This is really a socket option so the new name is clearer.
Since common/io/socket/tcp will contains a mix of options it makes sense to rename it to socket and cascade name changes as needed.
Prior to 2.25 the individual TCP keep-alive options were not being configured due to a missing header. In 2.25 they were being configured incorrectly due to a disconnect between the timeout specified in ms and what was expected by the TCP options, i.e. seconds.
Instead make the TCP keep-alive options directly configurable, with correct units and better testing. Keep-alive is enabled by default (though it can be defaulted to the system setting instead) and the rest of the options are not set by default. This is in line with what PostgreSQL does, though PostgreSQL does not allow keep-alive to be defaulted.
Also move configuration of TCP options before connect() as PostgreSQL does.
Features:
* Add lz4 compression support. Note that setting compress-type=lz4 will make new backups and archive incompatible (unrestorable) with prior versions of pgBackRest. (Reviewed by Cynthia Shang.)
* Add --dry-run option to the expire command. Use dry-run to see which backups/archive would be removed by the expire command without actually removing anything. (Contributed by Cynthia Shang, Luca Ferrari.)
Improvements:
* Improve performance of remote manifest build. (Suggested by Jens Wilke.)
* Fix detection of keepalive options on Linux. (Contributed by Marc Cousin.)
* Add configure host detection to set standards flags correctly. (Contributed by Marc Cousin.)
* Remove compress/compress-level options from commands where unused. 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. (Reviewed by Cynthia Shang.)
* Limit backup file copy size to size reported at backup start. If a file grows during the backup it will be reconstructed by WAL replay during recovery so there is no need to copy the additional data. (Reviewed by Cynthia Shang.)
Other storage*InfoList() functions do this but it was missed here.
memResize()/memFree() operations become more expensive as the mem context grows larger so freeing it periodically saves processing time.
If the work or result directories already contain data then the docs might be generated slightly differently. Doing a clean ensures they will always produce the same output (provided the code does not change).
Building the contributing document has some special requirements because it runs Docker in Docker so the repo path must align on the host and all Docker containers. Run `pgbackrest/doc/doc.pl` from within the home directory of the user that will do the doc build, e.g. `home/vagrant`. If the repo is not located directly in the home directory, e.g. `/home/vagrant/pgbackrest`, then a symlink may be used, e.g. `ln -s /path/to/repo /home/vagrant/pgbackrest`.
Mount the repo in the Vagrantfile at /home/vagrant/pgbackrest but provide a link from the old location at /backrest to make the transition less painful.
If a file grows during the backup it will be reconstructed by WAL replay during recovery so there is no need to copy the additional data.
This also reduces the likelihood of seeing torn pages during the copy. Torn pages can still occur in the middle of the file, though, so they must be handled.
This code stanza was not being included on Linux platforms because of a missing header file.
Also update the order of operations and make the timeout calculations more sensible.
The primary source for project info is now src/version.h.
The pgBackRestDoc::ProjectInfo module loads the project info from src/version.h at runtime so there is no need to update it.
This is consistent with the way BackRest and BackRest test were renamed way back in 18fd2523.
More modules will be moving to pgBackRestDoc soon so renaming now reduces churn later.
This directory was once the home of the production Perl code but since f0ef73db this is no longer true.
Move the modules to test in most cases, except where the module is expected to be useful for the doc engine beyond the expected lifetime of the Perl test code (about a year if all goes well).
The exception is pgBackRest::Version which requires more work to migrate since it is used to track pgBackRest versions.
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.
This was the interface between Perl and C introduced in 36a5349b but since f0ef73db has only been used by the Perl integration tests. This is expensive code to maintain just for testing.
The main dependency was the interface to storage, no matter where it was located, e.g. S3. Replace this with the new-introduced repo commands (d3c83453) that allow access to repo storage via the command line.
The other dependency was on various cfgOption* functions and CFGOPT_ constants that were convenient but not necessary. Replace these with hard-coded strings in most places and create new constants for commonly used values.
Remove all auto-generated Perl code. This means that the error list will no longer be maintained automatically so copy used errors to Common::Exception.pm. This file will need to be maintained manually going forward but there is not likely to be much churn as the Perl integration tests are being retired.
Update test.pl and related code to remove LibC builds.
Ding, dong, LibC is dead.
These commands are generally useful but more importantly they allow removing LibC by providing the Perl integration tests an alternate way to work with repository storage.
All the commands are currently internal only and should not be used on production repositories.
