Add option for parallel streaming of the transaction log while a
base backup is running, to get the logfiles before the server has
removed them.
Also add a tool called pg_receivexlog, which streams the transaction
log into files, creating a log archive without having to wait for
segments to complete, thus decreasing the window of data loss without
having to waste space using archive_timeout. This works best in
combination with archive_command - suggested usage docs etc coming later.
When streaming including WAL, the size estimate will always be incorrect,
since we don't know how much WAL is included. To make sure the output doesn't
look completely unreasonable, this patch increases the total size whenever we
go past the estimate, to make sure we never go above 100%.
The short-form -z switch didn't work, for lack of telling getopt_long
about it; and even if specified long-form, it failed to do anything,
because the various tests elsewhere in the file would take
Z_DEFAULT_COMPRESSION (which is -1) as meaning "don't compress".
Per bug #6060 from Shigehiro Honda, though I editorialized on his patch
a bit.
This code was accidentally part of the patch, it's only
needed for the code that's for 9.2. Not needing the timeline
also removes the need to call IDENTIFY_SYSTEM.
Noted by Peter E.
Add the current xlog insert location to the response of
IDENTIFY_SYSTEM, and adds result sets containing start
and stop location of backups to BASE_BACKUP responses.
When included, this makes the base backup a complete working
"clone" of the initial database, ready to have a postmaster
started against it without the need to set up any log archiving
or similar.
Magnus Hagander, reviewed by Fujii Masao and Heikki Linnakangas
The target of sscanf with a %o format had better be of integer width,
but "mode_t" conceivably isn't that. Another compiler warning seen
only on some platforms; this one I think is potentially a real bug
and not just a warning.
This tool makes it possible to do the pg_start_backup/
copy files/pg_stop_backup step in a single command.
There are still some steps to be done before this is a
complete backup solution, such as the ability to stream
the required WAL logs, but it's still usable, and
could do with some buildfarm coverage.
In passing, make the checkpoint request optionally
fast instead of hardcoding it.
Magnus Hagander, reviewed by Fujii Masao and Dimitri Fontaine