caleb-brown/redict
1
0
Fork 0
mirror of https://codeberg.org/redict/redict.git synced 2025-01-22 16:18:28 -05:00
Code Issues Actions Packages Projects Releases Wiki Activity

Sentinel: improve handling of known Sentinel instances.

Browse Source 
1. Bug #3035 is fixed (NULL pointer access). This was happening with the
   folling set of conditions:

* For some reason one of the Sentinels, let's call it Sentinel_A, changed ID (reconfigured from scratch), but is as the same address at which it used to be.

* Sentinel_A performs a failover and/or has a newer configuration compared to another Sentinel, that we call, Sentinel_B.

* Sentinel_B receives an HELLO message from Sentinel_A, where the address and/or ID is mismatched, but it is reporting a newer configuration for the master they are both monitoring.

2. Sentinels now must have an ID otherwise they are not loaded nor persisted in the configuration. This allows to have conflicting Sentinels with the same address since now the master->sentinels dictionary is indexed by Sentinel ID.

3. The code now detects if a Sentinel is annoucing itself with an IP/port pair already busy (of another Sentinel). The old Sentinel that had the same port/pair is set as having port 0, that means, the address is invalid. We may discover the right address later via HELLO messages.
This commit is contained in:
antirez 2016-01-27 16:27:49 +01:00
parent 5bc7e019e1
commit 751b5666fb
1 changed files with 34 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
src/sentinel.c
View File

@ -518,7 +518,7 @@ sentinelAddr *createSentinelAddr(char *hostname, int port) {
char ip[NET_IP_STR_LEN];
sentinelAddr *sa;
if (port <= 0 || port > 65535) {
if (port < 0 || port > 65535) {
errno = EINVAL;
return NULL;
}
@ -1132,7 +1132,8 @@ void sentinelDisconnectCallback(const redisAsyncContext *c, int status) {
* createSentinelAddr() function.
*
* The function may also fail and return NULL with errno set to EBUSY if
* a master or slave with the same name already exists. */
* a master with the same name, a slave with the same address, or a sentinel
* with the same ID already exists. */
sentinelRedisInstance *createSentinelRedisInstance(char *name, int flags, char *hostname, int port, int quorum, sentinelRedisInstance *master) {
sentinelRedisInstance *ri;
@ -1147,8 +1148,8 @@ sentinelRedisInstance *createSentinelRedisInstance(char *name, int flags, char *
addr = createSentinelAddr(hostname,port);
if (addr == NULL) return NULL;
/* For slaves and sentinel we use ip:port as name. */
if (flags & (SRI_SLAVE|SRI_SENTINEL)) {
/* For slaves use ip:port as name. */
if (flags & SRI_SLAVE) {
anetFormatAddr(slavename, sizeof(slavename), hostname, port);
name = slavename;
}
@ -1657,15 +1658,15 @@ char *sentinelHandleConfiguration(char **argv, int argc) {
(argc == 4 || argc == 5)) {
sentinelRedisInstance *si;
/* known-sentinel <name> <ip> <port> [runid] */
ri = sentinelGetMasterByName(argv[1]);
if (!ri) return "No such master with specified name.";
if ((si = createSentinelRedisInstance(NULL,SRI_SENTINEL,argv[2],
atoi(argv[3]), ri->quorum, ri)) == NULL)
{
return "Wrong hostname or port for sentinel.";
}
if (argc == 5) {
if (argc == 5) { /* Ignore the old form without runid. */
/* known-sentinel <name> <ip> <port> [runid] */
ri = sentinelGetMasterByName(argv[1]);
if (!ri) return "No such master with specified name.";
if ((si = createSentinelRedisInstance(argv[4],SRI_SENTINEL,argv[2],
atoi(argv[3]), ri->quorum, ri)) == NULL)
{
return "Wrong hostname or port for sentinel.";
}
si->runid = sdsnew(argv[4]);
sentinelTryConnectionSharing(si);
}
@ -1796,11 +1797,10 @@ void rewriteConfigSentinelOption(struct rewriteConfigState *state) {
di2 = dictGetIterator(master->sentinels);
while((de = dictNext(di2)) != NULL) {
ri = dictGetVal(de);
if (ri->runid == NULL) continue;
line = sdscatprintf(sdsempty(),
"sentinel known-sentinel %s %s %d%s%s",
master->name, ri->addr->ip, ri->addr->port,
ri->runid ? " " : "",
ri->runid ? ri->runid : "");
"sentinel known-sentinel %s %s %d %s",
master->name, ri->addr->ip, ri->addr->port, ri->runid);
rewriteConfigRewriteLine(state,"sentinel",line,1);
}
dictReleaseIterator(di2);
@ -1895,6 +1895,7 @@ void sentinelSetClientName(sentinelRedisInstance *ri, redisAsyncContext *c, char
* one of the two links (commands and pub/sub) is missing. */
void sentinelReconnectInstance(sentinelRedisInstance *ri) {
if (ri->link->disconnected == 0) return;
if (ri->addr->port == 0) return; /* port == 0 means invalid address. */
instanceLink *link = ri->link;
mstime_t now = mstime();
@ -2340,11 +2341,25 @@ void sentinelProcessHelloMessage(char *hello, int hello_len) {
if (removed) {
sentinelEvent(LL_NOTICE,"+sentinel-address-switch",master,
"%@ ip %s port %d for %s", token[0],port,token[2]);
} else {
/* Check if there is another Sentinel with the same address this
* new one is reporting. What we do if this happens is to set its
* port to 0, to signal the address is invalid. We'll update it
* later if we get an HELLO message. */
sentinelRedisInstance *other =
getSentinelRedisInstanceByAddrAndRunID(
master->sentinels, token[0],port,NULL);
if (other) {
sentinelEvent(LL_NOTICE,"+sentinel-invalid-addr",other,"%@");
other->addr->port = 0; /* It means: invalid address. */
sentinelUpdateSentinelAddressInAllMasters(other);
}
}
/* Add the new sentinel. */
si = createSentinelRedisInstance(NULL,SRI_SENTINEL,
si = createSentinelRedisInstance(token[2],SRI_SENTINEL,
token[0],port,master->quorum,master);
if (si) {
if (!removed) sentinelEvent(LL_NOTICE,"+sentinel",si,"%@");
/* The runid is NULL after a new instance creation and
@ -2366,7 +2381,7 @@ void sentinelProcessHelloMessage(char *hello, int hello_len) {
}
/* Update master info if received configuration is newer. */
if (master->config_epoch < master_config_epoch) {
if (si && master->config_epoch < master_config_epoch) {
master->config_epoch = master_config_epoch;
if (master_port != master->addr->port ||
strcmp(master->addr->ip, token[5]))