Support for read-only slaves. Semantical fixes.

This commit introduces support for read only slaves via redis.conf and CONFIG GET/SET commands. Also various semantical fixes are implemented here:

1) MULTI/EXEC with only read commands now work where the server is into a state where writes (or commands increasing memory usage) are not allowed. Before this patch everything inside a transaction would fail in this conditions.

2) Scripts just calling read-only commands will work against read only
slaves, when the server is out of memory, or when persistence is into an
error condition. Before the patch EVAL always failed in this condition.
This commit is contained in:
antirez
2012-03-20 17:32:48 +01:00
parent 7a0c72f345
commit f3fd419fc9
6 changed files with 85 additions and 17 deletions

View File

@ -202,6 +202,10 @@ void loadServerConfigFromString(char *config) {
if ((server.repl_serve_stale_data = yesnotoi(argv[1])) == -1) {
err = "argument must be 'yes' or 'no'"; goto loaderr;
}
} else if (!strcasecmp(argv[0],"slave-read-only") && argc == 2) {
if ((server.repl_slave_ro = yesnotoi(argv[1])) == -1) {
err = "argument must be 'yes' or 'no'"; goto loaderr;
}
} else if (!strcasecmp(argv[0],"rdbcompression") && argc == 2) {
if ((server.rdb_compression = yesnotoi(argv[1])) == -1) {
err = "argument must be 'yes' or 'no'"; goto loaderr;
@ -514,6 +518,11 @@ void configSetCommand(redisClient *c) {
if (yn == -1) goto badfmt;
server.repl_serve_stale_data = yn;
} else if (!strcasecmp(c->argv[2]->ptr,"slave-read-only")) {
int yn = yesnotoi(o->ptr);
if (yn == -1) goto badfmt;
server.repl_slave_ro = yn;
} else if (!strcasecmp(c->argv[2]->ptr,"dir")) {
if (chdir((char*)o->ptr) == -1) {
addReplyErrorFormat(c,"Changing directory: %s", strerror(errno));
@ -712,6 +721,8 @@ void configGetCommand(redisClient *c) {
server.aof_no_fsync_on_rewrite);
config_get_bool_field("slave-serve-stale-data",
server.repl_serve_stale_data);
config_get_bool_field("slave-read-only",
server.repl_slave_ro);
config_get_bool_field("stop-writes-on-bgsave-error",
server.stop_writes_on_bgsave_err);
config_get_bool_field("daemonize", server.daemonize);