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maxmemory implemented

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1 parent 16edf32 commit 3fd78bcd45338e96f761b558bfa68e83a8141f0b @antirez committed May 27, 2009
Showing with 101 additions and 20 deletions.
  1. +89 −20 redis.c
  2. +12 −0 redis.conf
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109 redis.c
@@ -80,8 +80,13 @@
#define REDIS_HT_MINSLOTS 16384 /* Never resize the HT under this */
/* Command flags */
-#define REDIS_CMD_BULK 1
-#define REDIS_CMD_INLINE 2
+#define REDIS_CMD_BULK 1 /* Bulk write command */
+#define REDIS_CMD_INLINE 2 /* Inline command */
+/* REDIS_CMD_DENYOOM reserves a longer comment: all the commands marked with
+ this flags will return an error when the 'maxmemory' option is set in the
+ config file and the server is using more than maxmemory bytes of memory.
+ In short this commands are denied on low memory conditions. */
+#define REDIS_CMD_DENYOOM 4
/* Object types */
#define REDIS_STRING 0
@@ -246,6 +251,7 @@ struct redisServer {
redisClient *master; /* client that is master for this slave */
int replstate;
unsigned int maxclients;
+ unsigned int maxmemory;
/* Sort parameters - qsort_r() is only available under BSD so we
* have to take this state global, in order to pass it to sortCompare() */
int sort_desc;
@@ -307,6 +313,7 @@ static int deleteKey(redisDb *db, robj *key);
static time_t getExpire(redisDb *db, robj *key);
static int setExpire(redisDb *db, robj *key, time_t when);
static void updateSalvesWaitingBgsave(int bgsaveerr);
+static void freeMemoryIfNeeded(void);
static void authCommand(redisClient *c);
static void pingCommand(redisClient *c);
@@ -371,38 +378,38 @@ static void slaveofCommand(redisClient *c);
static struct redisServer server; /* server global state */
static struct redisCommand cmdTable[] = {
{"get",getCommand,2,REDIS_CMD_INLINE},
- {"set",setCommand,3,REDIS_CMD_BULK},
- {"setnx",setnxCommand,3,REDIS_CMD_BULK},
+ {"set",setCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
+ {"setnx",setnxCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
{"del",delCommand,-2,REDIS_CMD_INLINE},
{"exists",existsCommand,2,REDIS_CMD_INLINE},
- {"incr",incrCommand,2,REDIS_CMD_INLINE},
- {"decr",decrCommand,2,REDIS_CMD_INLINE},
+ {"incr",incrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"decr",decrCommand,2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
{"mget",mgetCommand,-2,REDIS_CMD_INLINE},
- {"rpush",rpushCommand,3,REDIS_CMD_BULK},
- {"lpush",lpushCommand,3,REDIS_CMD_BULK},
+ {"rpush",rpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
+ {"lpush",lpushCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
{"rpop",rpopCommand,2,REDIS_CMD_INLINE},
{"lpop",lpopCommand,2,REDIS_CMD_INLINE},
{"llen",llenCommand,2,REDIS_CMD_INLINE},
{"lindex",lindexCommand,3,REDIS_CMD_INLINE},
- {"lset",lsetCommand,4,REDIS_CMD_BULK},
+ {"lset",lsetCommand,4,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
{"lrange",lrangeCommand,4,REDIS_CMD_INLINE},
{"ltrim",ltrimCommand,4,REDIS_CMD_INLINE},
{"lrem",lremCommand,4,REDIS_CMD_BULK},
- {"sadd",saddCommand,3,REDIS_CMD_BULK},
+ {"sadd",saddCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
{"srem",sremCommand,3,REDIS_CMD_BULK},
{"smove",smoveCommand,4,REDIS_CMD_BULK},
{"sismember",sismemberCommand,3,REDIS_CMD_BULK},
{"scard",scardCommand,2,REDIS_CMD_INLINE},
- {"sinter",sinterCommand,-2,REDIS_CMD_INLINE},
- {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE},
- {"sunion",sunionCommand,-2,REDIS_CMD_INLINE},
- {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE},
- {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE},
- {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE},
+ {"sinter",sinterCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"sunion",sunionCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
{"smembers",sinterCommand,2,REDIS_CMD_INLINE},
- {"incrby",incrbyCommand,3,REDIS_CMD_INLINE},
- {"decrby",decrbyCommand,3,REDIS_CMD_INLINE},
- {"getset",getSetCommand,3,REDIS_CMD_BULK},
+ {"incrby",incrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"decrby",decrbyCommand,3,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
+ {"getset",getSetCommand,3,REDIS_CMD_BULK|REDIS_CMD_DENYOOM},
{"randomkey",randomkeyCommand,1,REDIS_CMD_INLINE},
{"select",selectCommand,2,REDIS_CMD_INLINE},
{"move",moveCommand,3,REDIS_CMD_INLINE},
@@ -422,7 +429,7 @@ static struct redisCommand cmdTable[] = {
{"sync",syncCommand,1,REDIS_CMD_INLINE},
{"flushdb",flushdbCommand,1,REDIS_CMD_INLINE},
{"flushall",flushallCommand,1,REDIS_CMD_INLINE},
- {"sort",sortCommand,-2,REDIS_CMD_INLINE},
+ {"sort",sortCommand,-2,REDIS_CMD_INLINE|REDIS_CMD_DENYOOM},
{"info",infoCommand,1,REDIS_CMD_INLINE},
{"monitor",monitorCommand,1,REDIS_CMD_INLINE},
{"ttl",ttlCommand,2,REDIS_CMD_INLINE},
@@ -864,6 +871,7 @@ static void initServerConfig() {
server.requirepass = NULL;
server.shareobjects = 0;
server.maxclients = 0;
+ server.maxmemory = 0;
ResetServerSaveParams();
appendServerSaveParams(60*60,1); /* save after 1 hour and 1 change */
@@ -1024,6 +1032,8 @@ static void loadServerConfig(char *filename) {
}
} else if (!strcasecmp(argv[0],"maxclients") && argc == 2) {
server.maxclients = atoi(argv[1]);
+ } else if (!strcasecmp(argv[0],"maxmemory") && argc == 2) {
+ server.maxmemory = atoi(argv[1]);
} else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
server.masterhost = sdsnew(argv[1]);
server.masterport = atoi(argv[2]);
@@ -1207,6 +1217,9 @@ static int processCommand(redisClient *c) {
struct redisCommand *cmd;
long long dirty;
+ /* Free some memory if needed (maxmemory setting) */
+ if (server.maxmemory) freeMemoryIfNeeded();
+
/* The QUIT command is handled as a special case. Normal command
* procs are unable to close the client connection safely */
if (!strcasecmp(c->argv[0]->ptr,"quit")) {
@@ -1223,6 +1236,10 @@ static int processCommand(redisClient *c) {
addReplySds(c,sdsnew("-ERR wrong number of arguments\r\n"));
resetClient(c);
return 1;
+ } else if (server.maxmemory && cmd->flags & REDIS_CMD_DENYOOM && zmalloc_used_memory() > server.maxmemory) {
+ addReplySds(c,sdsnew("-ERR command not allowed when used memory > 'maxmemory'\r\n"));
+ resetClient(c);
+ return 1;
} else if (cmd->flags & REDIS_CMD_BULK && c->bulklen == -1) {
int bulklen = atoi(c->argv[c->argc-1]->ptr);
@@ -3974,6 +3991,58 @@ static void slaveofCommand(redisClient *c) {
addReply(c,shared.ok);
}
+/* ============================ Maxmemory directive ======================== */
+
+/* This function gets called when 'maxmemory' is set on the config file to limit
+ * the max memory used by the server, and we are out of memory.
+ * This function will try to, in order:
+ *
+ * - Free objects from the free list
+ * - Try to remove keys with an EXPIRE set
+ *
+ * It is not possible to free enough memory to reach used-memory < maxmemory
+ * the server will start refusing commands that will enlarge even more the
+ * memory usage.
+ */
+static void freeMemoryIfNeeded(void) {
+ while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) {
+ if (listLength(server.objfreelist)) {
+ robj *o;
+
+ listNode *head = listFirst(server.objfreelist);
+ o = listNodeValue(head);
+ listDelNode(server.objfreelist,head);
+ zfree(o);
+ } else {
+ int j, k, freed = 0;
+
+ for (j = 0; j < server.dbnum; j++) {
+ int minttl = -1;
+ robj *minkey = NULL;
+ struct dictEntry *de;
+
+ if (dictSize(server.db[j].expires)) {
+ freed = 1;
+ /* From a sample of three keys drop the one nearest to
+ * the natural expire */
+ for (k = 0; k < 3; k++) {
+ time_t t;
+
+ de = dictGetRandomKey(server.db[j].expires);
+ t = (time_t) dictGetEntryVal(de);
+ if (minttl == -1 || t < minttl) {
+ minkey = dictGetEntryKey(de);
+ minttl = t;
+ }
+ }
+ deleteKey(server.db+j,minkey);
+ }
+ }
+ if (!freed) return; /* nothing to free... */
+ }
+ }
+}
+
/* =================================== Main! ================================ */
#ifdef __linux__
View
12 redis.conf
@@ -88,6 +88,18 @@ databases 16
# maxclients 128
+# Don't use more memory than the specified amount of bytes.
+# When the memory limit is reached Redis will try to remove keys with an
+# EXPIRE set. It will try to start freeing keys that are going to expire
+# in little time and preserve keys with a longer time to live.
+# Redis will also try to remove objects from free lists if possible.
+#
+# If all this fails, Redis will start to reply with errors to commands
+# that will use more memory, like SET, LPUSH, and so on, and will continue
+# to reply to most read-only commands like GET.
+
+# maxmemory <bytes>
+
############################### ADVANCED CONFIG ###############################
# Glue small output buffers together in order to send small replies in a

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