implement repl_auto_resync against 2.6

.gitignore

@@ -1,4 +1,5 @@
 .*.swp
+*~
 *.o
 *.rdb
 *.log

redis.conf

@@ -196,6 +196,11 @@ slave-read-only yes
 #
 # repl-timeout 60
 
+# The following option controls whether a redis slave will automatically
+# try to resync with the master if contact is lost. The default is 'yes'
+#
+# repl-auto-resync no
+
 # The slave priority is an integer number published by Redis in the INFO output.
 # It is used by Redis Sentinel in order to select a slave to promote into a
 # master if the master is no longer working correctly.

src/config.c

@@ -230,7 +230,13 @@ void loadServerConfigFromString(char *config) {
                 err = "repl-timeout must be 1 or greater";
                 goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"masterauth") && argc == 2) {
+        } else if (!strcasecmp(argv[0],"repl-auto-resync") && argc == 2) {
+            server.repl_auto_resync = yesnotoi(argv[1]);
+            if (server.repl_auto_resync == -1) {
+                err = "repl-auto-resync must be 'yes' or 'no'";
+                goto loaderr;
+            }
+		} else if (!strcasecmp(argv[0],"masterauth") && argc == 2) {
         	server.masterauth = zstrdup(argv[1]);
         } else if (!strcasecmp(argv[0],"slave-serve-stale-data") && argc == 2) {
             if ((server.repl_serve_stale_data = yesnotoi(argv[1])) == -1) {

src/networking.c

@@ -647,7 +647,11 @@ void freeClient(redisClient *c) {
     /* Case 2: we lost the connection with the master. */
     if (c->flags & REDIS_MASTER) {
         server.master = NULL;
-        server.repl_state = REDIS_REPL_CONNECT;
+        if (server.repl_auto_resync) {
+            server.repl_state = REDIS_REPL_CONNECT;
+        } else {
+            server.repl_state = REDIS_REPL_NONE;
+        }
         server.repl_down_since = server.unixtime;
         /* We lost connection with our master, force our slaves to resync
          * with us as well to load the new data set.

src/redis.c

@@ -1154,6 +1154,7 @@ void initServerConfig() {
     server.masterhost = NULL;
     server.masterport = 6379;
     server.master = NULL;
+    server.repl_auto_resync = 1;
     server.repl_state = REDIS_REPL_NONE;
     server.repl_syncio_timeout = REDIS_REPL_SYNCIO_TIMEOUT;
     server.repl_serve_stale_data = 1;

src/redis.h

@@ -602,6 +602,7 @@ struct redisServer {
     int masterport;                 /* Port of master */
     int repl_ping_slave_period;     /* Master pings the slave every N seconds */
     int repl_timeout;               /* Timeout after N seconds of master idle */
+    int repl_auto_resync;           /* Automatically reconnect to master? */
     redisClient *master;     /* Client that is master for this slave */
     int repl_syncio_timeout; /* Timeout for synchronous I/O calls */
     int repl_state;          /* Replication status if the instance is a slave */