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mirror of https://github.com/pgbackrest/pgbackrest.git synced 2024-12-14 10:13:05 +02:00
pgbackrest/lib/pgBackRest/Archive/Common.pm
David Steele c94e52f697 Remove error when overlapping timelines are detected.
Overlapping timelines are valid in many Point-in-Time-Recovery (PITR) scenarios.

Reported by blogh.
2017-10-16 14:34:44 -04:00

428 lines
15 KiB
Perl

####################################################################################################################################
# ARCHIVE COMMON MODULE
####################################################################################################################################
package pgBackRest::Archive::Common;
use strict;
use warnings FATAL => qw(all);
use Carp qw(confess);
use Exporter qw(import);
our @EXPORT = qw();
use Fcntl qw(SEEK_CUR O_RDONLY);
use File::Basename qw(dirname);
use pgBackRest::Db;
use pgBackRest::DbVersion;
use pgBackRest::Common::Exception;
use pgBackRest::Common::Log;
use pgBackRest::Common::Wait;
use pgBackRest::Config::Config;
use pgBackRest::Protocol::Storage::Helper;
use pgBackRest::Storage::Helper;
####################################################################################################################################
# RegEx constants
####################################################################################################################################
use constant REGEX_ARCHIVE_DIR_DB_VERSION => '^[0-9]+\.[0-9]+-[0-9]+$';
push @EXPORT, qw(REGEX_ARCHIVE_DIR_DB_VERSION);
use constant REGEX_ARCHIVE_DIR_WAL => '^[0-F]{16}$';
push @EXPORT, qw(REGEX_ARCHIVE_DIR_WAL);
####################################################################################################################################
# PostgreSQL WAL system id offset
####################################################################################################################################
use constant PG_WAL_SYSTEM_ID_OFFSET_GTE_93 => 20;
push @EXPORT, qw(PG_WAL_SYSTEM_ID_OFFSET_GTE_93);
use constant PG_WAL_SYSTEM_ID_OFFSET_LT_93 => 12;
push @EXPORT, qw(PG_WAL_SYSTEM_ID_OFFSET_LT_93);
####################################################################################################################################
# WAL segment size
####################################################################################################################################
use constant PG_WAL_SEGMENT_SIZE => 16777216;
push @EXPORT, qw(PG_WAL_SEGMENT_SIZE);
####################################################################################################################################
# PostgreSQL WAL magic
####################################################################################################################################
my $oWalMagicHash =
{
hex('0xD062') => PG_VERSION_83,
hex('0xD063') => PG_VERSION_84,
hex('0xD064') => PG_VERSION_90,
hex('0xD066') => PG_VERSION_91,
hex('0xD071') => PG_VERSION_92,
hex('0xD075') => PG_VERSION_93,
hex('0xD07E') => PG_VERSION_94,
hex('0xD087') => PG_VERSION_95,
hex('0xD093') => PG_VERSION_96,
hex('0xD097') => PG_VERSION_10,
};
####################################################################################################################################
# lsnNormalize
#
# Generates a normalized form from an LSN that can be used for comparison.
####################################################################################################################################
sub lsnNormalize
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strLsn,
) =
logDebugParam
(
__PACKAGE__ . '::lsnFile', \@_,
{name => 'strLsn', trace => true},
);
# Split the LSN into major and minor parts
my @stryLsnSplit = split('/', $strLsn);
if (@stryLsnSplit != 2)
{
confess &log(ASSERT, "invalid lsn ${strLsn}");
}
my $strLsnNormal = uc(sprintf("%08s%08s", $stryLsnSplit[0], $stryLsnSplit[1]));
# Return from function and log return values if any
return logDebugReturn
(
$strOperation,
{name => 'strLsnNormal', value => $strLsnNormal, trace => true}
);
}
push @EXPORT, qw(lsnNormalize);
####################################################################################################################################
# lsnFileRange
#
# Generates a range of WAL filenames given the start and stop LSN. For pre-9.3 databases, use bSkipFF to exclude the FF that
# prior versions did not generate.
####################################################################################################################################
sub lsnFileRange
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strLsnStart,
$strLsnStop,
$strDbVersion,
) =
logDebugParam
(
__PACKAGE__ . '::lsnFileRange', \@_,
{name => 'strLsnStart'},
{name => 'strLsnStop'},
{name => '$strDbVersion'},
);
# Working variables
my @stryArchive;
my $iArchiveIdx = 0;
my $bSkipFF = $strDbVersion < PG_VERSION_93;
# Iterate through all archive logs between start and stop
my @stryArchiveSplit = split('/', $strLsnStart);
my $iStartMajor = hex($stryArchiveSplit[0]);
my $iStartMinor = hex(substr(sprintf("%08s", $stryArchiveSplit[1]), 0, 2));
@stryArchiveSplit = split('/', $strLsnStop);
my $iStopMajor = hex($stryArchiveSplit[0]);
my $iStopMinor = hex(substr(sprintf("%08s", $stryArchiveSplit[1]), 0, 2));
$stryArchive[$iArchiveIdx] = uc(sprintf("%08x%08x", $iStartMajor, $iStartMinor));
$iArchiveIdx += 1;
while (!($iStartMajor == $iStopMajor && $iStartMinor == $iStopMinor))
{
$iStartMinor += 1;
if ($bSkipFF && $iStartMinor == 255 || !$bSkipFF && $iStartMinor == 256)
{
$iStartMajor += 1;
$iStartMinor = 0;
}
$stryArchive[$iArchiveIdx] = uc(sprintf("%08x%08x", $iStartMajor, $iStartMinor));
$iArchiveIdx += 1;
}
# Return from function and log return values if any
return logDebugReturn
(
$strOperation,
{name => 'stryWalFileName', value => \@stryArchive}
);
}
push @EXPORT, qw(lsnFileRange);
####################################################################################################################################
# walInfo
#
# Retrieve information such as db version and system identifier from a WAL segment.
####################################################################################################################################
sub walInfo
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strWalFile,
) =
logDebugParam
(
__PACKAGE__ . '::walInfo', \@_,
{name => 'strWalFile'}
);
# Open the WAL segment and read magic number
#-------------------------------------------------------------------------------------------------------------------------------
my $hFile;
my $tBlock;
sysopen($hFile, $strWalFile, O_RDONLY)
or confess &log(ERROR, "unable to open ${strWalFile}", ERROR_FILE_OPEN);
# Read magic
sysread($hFile, $tBlock, 2) == 2
or confess &log(ERROR, "unable to read wal magic");
my $iMagic = unpack('S', $tBlock);
# Map the WAL magic number to the version of PostgreSQL.
#
# The magic number can be found in src/include/access/xlog_internal.h The offset can be determined by counting bytes in the
# XLogPageHeaderData struct, though this value rarely changes.
#-------------------------------------------------------------------------------------------------------------------------------
my $strDbVersion = $$oWalMagicHash{$iMagic};
if (!defined($strDbVersion))
{
confess &log(ERROR, "unexpected WAL magic 0x" . sprintf("%X", $iMagic) . "\n" .
'HINT: is this version of PostgreSQL supported?',
ERROR_VERSION_NOT_SUPPORTED);
}
# Map the WAL PostgreSQL version to the system identifier offset. The offset can be determined by counting bytes in the
# XLogPageHeaderData struct, though this value rarely changes.
#-------------------------------------------------------------------------------------------------------------------------------
my $iSysIdOffset = $strDbVersion >= PG_VERSION_93 ? PG_WAL_SYSTEM_ID_OFFSET_GTE_93 : PG_WAL_SYSTEM_ID_OFFSET_LT_93;
# Check flags to be sure the long header is present (this is an extra check to be sure the system id exists)
#-------------------------------------------------------------------------------------------------------------------------------
sysread($hFile, $tBlock, 2) == 2
or confess &log(ERROR, "unable to read wal info");
my $iFlag = unpack('S', $tBlock);
# Make sure that the long header is present or there won't be a system id
$iFlag & 2
or confess &log(ERROR, "expected long header in flags " . sprintf("%x", $iFlag));
# Get the system id
#-------------------------------------------------------------------------------------------------------------------------------
sysseek($hFile, $iSysIdOffset, SEEK_CUR)
or confess &log(ERROR, "unable to read padding");
sysread($hFile, $tBlock, 8) == 8
or confess &log(ERROR, "unable to read database system identifier");
length($tBlock) == 8
or confess &log(ERROR, "block is incorrect length");
close($hFile);
my $ullDbSysId = unpack('Q', $tBlock);
# Return from function and log return values if any
return logDebugReturn
(
$strOperation,
{name => 'strDbVersion', value => $strDbVersion},
{name => 'ullDbSysId', value => $ullDbSysId}
);
}
push @EXPORT, qw(walInfo);
####################################################################################################################################
# walSegmentFind
#
# Returns the filename of a WAL segment in the archive. Optionally, a wait time can be specified. In this case an error will be
# thrown when the WAL segment is not found. If the same WAL segment with multiple checksums is found then error.
####################################################################################################################################
sub walSegmentFind
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$oStorageRepo,
$strArchiveId,
$strWalSegment,
$iWaitSeconds,
) =
logDebugParam
(
__PACKAGE__ . '::walSegmentFind', \@_,
{name => 'oStorageRepo'},
{name => 'strArchiveId'},
{name => 'strWalSegment'},
{name => 'iWaitSeconds', required => false},
);
# Error if not a segment
if (!walIsSegment($strWalSegment))
{
confess &log(ERROR, "${strWalSegment} is not a WAL segment", ERROR_ASSERT);
}
# Loop and wait for file to appear
my $oWait = waitInit($iWaitSeconds);
my @stryWalFileName;
do
{
# Get the name of the requested WAL segment (may have compression extension)
push(@stryWalFileName, $oStorageRepo->list(
STORAGE_REPO_ARCHIVE . "/${strArchiveId}/" . substr($strWalSegment, 0, 16),
{strExpression =>
'^' . substr($strWalSegment, 0, 24) . (walIsPartial($strWalSegment) ? "\\.partial" : '') .
"-[0-f]{40}(\\." . COMPRESS_EXT . "){0,1}\$",
bIgnoreMissing => true}));
}
while (@stryWalFileName == 0 && waitMore($oWait));
# If there is more than one matching archive file then there is a serious issue - either a bug in the archiver or the user has
# copied files around or removed archive.info.
if (@stryWalFileName > 1)
{
confess &log(ERROR,
"duplicates found in archive for WAL segment ${strWalSegment}: " . join(', ', @stryWalFileName) .
"\nHINT: are multiple primaries archiving to this stanza?",
ERROR_ARCHIVE_DUPLICATE);
}
# If waiting and no WAL segment was found then throw an error
if (@stryWalFileName == 0 && defined($iWaitSeconds))
{
confess &log(ERROR, "could not find WAL segment ${strWalSegment} after ${iWaitSeconds} second(s)", ERROR_ARCHIVE_TIMEOUT);
}
# Return from function and log return values if any
return logDebugReturn
(
$strOperation,
{name => 'strWalFileName', value => $stryWalFileName[0]}
);
}
push @EXPORT, qw(walSegmentFind);
####################################################################################################################################
# walPath
#
# Generates the location of the wal directory using a relative wal path and the supplied db path.
####################################################################################################################################
sub walPath
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strWalFile,
$strDbPath,
$strCommand,
) =
logDebugParam
(
__PACKAGE__ . '::walPath', \@_,
{name => 'strWalFile', trace => true},
{name => 'strDbPath', trace => true, required => false},
{name => 'strCommand', trace => true},
);
if (index($strWalFile, '/') != 0)
{
if (!defined($strDbPath))
{
confess &log(ERROR,
"option 'db-path' must be specified when relative wal paths are used\n" .
"HINT: Is \%f passed to ${strCommand} instead of \%p?\n" .
"HINT: PostgreSQL may pass relative paths even with \%p depending on the environment.",
ERROR_OPTION_REQUIRED);
}
$strWalFile = "${strDbPath}/${strWalFile}";
}
# Return from function and log return values if any
return logDebugReturn
(
$strOperation,
{name => 'strWalFile', value => $strWalFile, trace => true}
);
}
push @EXPORT, qw(walPath);
####################################################################################################################################
# walIsSegment
#
# Is the file a segment or some other file (e.g. .history, .backup, etc).
####################################################################################################################################
sub walIsSegment
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strWalFile,
) =
logDebugParam
(
__PACKAGE__ . '::walIsSegment', \@_,
{name => 'strWalFile', trace => true},
);
return $strWalFile =~ /^[0-F]{24}(\.partial){0,1}$/ ? true : false;
}
push @EXPORT, qw(walIsSegment);
####################################################################################################################################
# walIsPartial
#
# Is the file a segment and partial.
####################################################################################################################################
sub walIsPartial
{
# Assign function parameters, defaults, and log debug info
my
(
$strOperation,
$strWalFile,
) =
logDebugParam
(
__PACKAGE__ . '::walIsPartial', \@_,
{name => 'strWalFile', trace => true},
);
return walIsSegment($strWalFile) && $strWalFile =~ /\.partial$/ ? true : false;
}
push @EXPORT, qw(walIsPartial);
1;