rewriteAppendOnlyFileBackground() failure fix

It is possible to do BGREWRITEAOF even if appendonly=no. This is by design.
stopAppendonly() didn't turn off aof_rewrite_scheduled (it can be turned on
again by BGREWRITEAOF even while appendonly is off anyway).
After configuring `appendonly yes` it will see that the state is AOF_OFF,
there's no RDB fork, so it will do rewriteAppendOnlyFileBackground() which
will fail since the aof_child_pid is set (was scheduled and started by cron).

Solution:
stopAppendonly() will turn off the schedule flag (regardless of who asked for it).
startAppendonly() will terminate any existing fork and start a new one (so it is the most recent).
This commit is contained in:
Guy Benoish 2017-03-07 20:58:54 +02:00 committed by antirez
parent 5807397460
commit 0c030dea73

View File

@ -203,6 +203,26 @@ void aof_background_fsync(int fd) {
bioCreateBackgroundJob(BIO_AOF_FSYNC,(void*)(long)fd,NULL,NULL);
}
/* Kills an AOFRW child process if exists */
static void killAppendOnlyChild(void) {
int statloc;
/* No AOFRW child? return. */
if (server.aof_child_pid == -1) return;
/* Kill AOFRW child, wait for child exit. */
serverLog(LL_NOTICE,"Killing running AOF rewrite child: %ld",
(long) server.aof_child_pid);
if (kill(server.aof_child_pid,SIGUSR1) != -1) {
while(wait3(&statloc,0,NULL) != server.aof_child_pid);
}
/* Reset the buffer accumulating changes while the child saves. */
aofRewriteBufferReset();
aofRemoveTempFile(server.aof_child_pid);
server.aof_child_pid = -1;
server.aof_rewrite_time_start = -1;
/* Close pipes used for IPC between the two processes. */
aofClosePipes();
}
/* Called when the user switches from "appendonly yes" to "appendonly no"
* at runtime using the CONFIG command. */
void stopAppendOnly(void) {
@ -214,23 +234,7 @@ void stopAppendOnly(void) {
server.aof_fd = -1;
server.aof_selected_db = -1;
server.aof_state = AOF_OFF;
/* rewrite operation in progress? kill it, wait child exit */
if (server.aof_child_pid != -1) {
int statloc;
serverLog(LL_NOTICE,"Killing running AOF rewrite child: %ld",
(long) server.aof_child_pid);
if (kill(server.aof_child_pid,SIGUSR1) != -1) {
while(wait3(&statloc,0,NULL) != server.aof_child_pid);
}
/* reset the buffer accumulating changes while the child saves */
aofRewriteBufferReset();
aofRemoveTempFile(server.aof_child_pid);
server.aof_child_pid = -1;
server.aof_rewrite_time_start = -1;
/* close pipes used for IPC between the two processes. */
aofClosePipes();
}
killAppendOnlyChild();
}
/* Called when the user switches from "appendonly no" to "appendonly yes"
@ -255,10 +259,16 @@ int startAppendOnly(void) {
if (server.rdb_child_pid != -1) {
server.aof_rewrite_scheduled = 1;
serverLog(LL_WARNING,"AOF was enabled but there is already a child process saving an RDB file on disk. An AOF background was scheduled to start when possible.");
} else if (rewriteAppendOnlyFileBackground() == C_ERR) {
close(newfd);
serverLog(LL_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
return C_ERR;
} else {
if (server.aof_child_pid != -1) {
serverLog(LL_WARNING,"AOF was enabled but there is already an AOF rewriting in background. Stopping background AOF and starting a rewrite now.");
killAppendOnlyChild();
}
if (rewriteAppendOnlyFileBackground() == C_ERR) {
close(newfd);
serverLog(LL_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
return C_ERR;
}
}
/* We correctly switched on AOF, now wait for the rewrite to be complete
* in order to append data on disk. */