@ -25,6 +25,7 @@
# include "libpq/pqformat.h"
# include "miscadmin.h"
# include "nodes/pg_list.h"
# include "pgtar.h"
# include "pgstat.h"
# include "replication/basebackup.h"
# include "replication/walsender.h"
@ -34,7 +35,8 @@
# include "utils/builtins.h"
# include "utils/elog.h"
# include "utils/ps_status.h"
# include "pgtar.h"
# include "utils/timestamp.h"
typedef struct
{
@ -43,6 +45,7 @@ typedef struct
bool fastcheckpoint ;
bool nowait ;
bool includewal ;
uint32 maxrate ;
} basebackup_options ;
@ -60,6 +63,7 @@ static void perform_base_backup(basebackup_options *opt, DIR *tblspcdir);
static void parse_basebackup_options ( List * options , basebackup_options * opt ) ;
static void SendXlogRecPtrResult ( XLogRecPtr ptr , TimeLineID tli ) ;
static int compareWalFileNames ( const void * a , const void * b ) ;
static void throttle ( size_t increment ) ;
/* Was the backup currently in-progress initiated in recovery mode? */
static bool backup_started_in_recovery = false ;
@ -72,6 +76,23 @@ static char *statrelpath = NULL;
*/
# define TAR_SEND_SIZE 32768
/*
* How frequently to throttle , as a fraction of the specified rate - second .
*/
# define THROTTLING_FREQUENCY 8
/* The actual number of bytes, transfer of which may cause sleep. */
static uint64 throttling_sample ;
/* Amount of data already transfered but not yet throttled. */
static int64 throttling_counter ;
/* The minimum time required to transfer throttling_sample bytes. */
static int64 elapsed_min_unit ;
/* The last check of the transfer rate. */
static int64 throttled_last ;
typedef struct
{
char * oid ;
@ -203,6 +224,29 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
/* Send tablespace header */
SendBackupHeader ( tablespaces ) ;
/* Setup and activate network throttling, if client requested it */
if ( opt - > maxrate > 0 )
{
throttling_sample = opt - > maxrate * 1024 / THROTTLING_FREQUENCY ;
/*
* The minimum amount of time for throttling_sample
* bytes to be transfered .
*/
elapsed_min_unit = USECS_PER_SEC / THROTTLING_FREQUENCY ;
/* Enable throttling. */
throttling_counter = 0 ;
/* The 'real data' starts now (header was ignored). */
throttled_last = GetCurrentIntegerTimestamp ( ) ;
}
else
{
/* Disable throttling. */
throttling_counter = - 1 ;
}
/* Send off our tablespaces one by one */
foreach ( lc , tablespaces )
{
@ -430,6 +474,8 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
( errmsg ( " base backup could not send data, aborting backup " ) ) ) ;
len + = cnt ;
throttle ( cnt ) ;
if ( len = = XLogSegSize )
break ;
}
@ -500,6 +546,7 @@ parse_basebackup_options(List *options, basebackup_options *opt)
bool o_fast = false ;
bool o_nowait = false ;
bool o_wal = false ;
bool o_maxrate = false ;
MemSet ( opt , 0 , sizeof ( * opt ) ) ;
foreach ( lopt , options )
@ -551,6 +598,25 @@ parse_basebackup_options(List *options, basebackup_options *opt)
opt - > includewal = true ;
o_wal = true ;
}
else if ( strcmp ( defel - > defname , " max_rate " ) = = 0 )
{
long maxrate ;
if ( o_maxrate )
ereport ( ERROR ,
( errcode ( ERRCODE_SYNTAX_ERROR ) ,
errmsg ( " duplicate option \" %s \" " , defel - > defname ) ) ) ;
maxrate = intVal ( defel - > arg ) ;
if ( maxrate < MAX_RATE_LOWER | | maxrate > MAX_RATE_UPPER )
ereport ( ERROR ,
( errcode ( ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE ) ,
errmsg ( " %d is outside the valid range for parameter \" %s \" (%d .. %d) " ,
( int ) maxrate , " MAX_RATE " , MAX_RATE_LOWER , MAX_RATE_UPPER ) ) ) ;
opt - > maxrate = ( uint32 ) maxrate ;
o_maxrate = true ;
}
else
elog ( ERROR , " option \" %s \" not recognized " ,
defel - > defname ) ;
@ -1112,6 +1178,7 @@ sendFile(char *readfilename, char *tarfilename, struct stat * statbuf,
( errmsg ( " base backup could not send data, aborting backup " ) ) ) ;
len + = cnt ;
throttle ( cnt ) ;
if ( len > = statbuf - > st_size )
{
@ -1133,10 +1200,14 @@ sendFile(char *readfilename, char *tarfilename, struct stat * statbuf,
cnt = Min ( sizeof ( buf ) , statbuf - > st_size - len ) ;
pq_putmessage ( ' d ' , buf , cnt ) ;
len + = cnt ;
throttle ( cnt ) ;
}
}
/* Pad to 512 byte boundary, per tar format requirements */
/*
* Pad to 512 byte boundary , per tar format requirements . ( This small
* piece of data is probably not worth throttling . )
*/
pad = ( ( len + 511 ) & ~ 511 ) - len ;
if ( pad > 0 )
{
@ -1162,3 +1233,65 @@ _tarWriteHeader(const char *filename, const char *linktarget,
pq_putmessage ( ' d ' , h , 512 ) ;
}
/*
* Increment the network transfer counter by the given number of bytes ,
* and sleep if necessary to comply with the requested network transfer
* rate .
*/
static void
throttle ( size_t increment )
{
int64 elapsed ,
elapsed_min ,
sleep ;
int wait_result ;
if ( throttling_counter < 0 )
return ;
throttling_counter + = increment ;
if ( throttling_counter < throttling_sample )
return ;
/* Time elapsed since the last measurement (and possible wake up). */
elapsed = GetCurrentIntegerTimestamp ( ) - throttled_last ;
/* How much should have elapsed at minimum? */
elapsed_min = elapsed_min_unit * ( throttling_counter / throttling_sample ) ;
sleep = elapsed_min - elapsed ;
/* Only sleep if the transfer is faster than it should be. */
if ( sleep > 0 )
{
ResetLatch ( & MyWalSnd - > latch ) ;
/*
* ( TAR_SEND_SIZE / throttling_sample * elapsed_min_unit ) should be
* the maximum time to sleep . Thus the cast to long is safe .
*/
wait_result = WaitLatch ( & MyWalSnd - > latch ,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH ,
( long ) ( sleep / 1000 ) ) ;
}
else
{
/*
* The actual transfer rate is below the limit . A negative value would
* distort the adjustment of throttled_last .
*/
wait_result = 0 ;
sleep = 0 ;
}
/*
* Only a whole multiple of throttling_sample was processed . The rest will
* be done during the next call of this function .
*/
throttling_counter % = throttling_sample ;
/* Once the (possible) sleep has ended, new period starts. */
if ( wait_result & WL_TIMEOUT )
throttled_last + = elapsed + sleep ;
else if ( sleep > 0 )
/* Sleep was necessary but might have been interrupted. */
throttled_last = GetCurrentIntegerTimestamp ( ) ;
}
Alvaro Herrera
12 years ago