redisClient *master; /* client that is master for this slave */
int replstate;
unsigned int maxclients;
- unsigned long maxmemory;
+ unsigned long long maxmemory;
unsigned int blockedclients;
/* 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 vm_enabled;
off_t vm_page_size;
off_t vm_pages;
- long vm_max_memory;
+ unsigned long long vm_max_memory;
/* Virtual memory state */
FILE *vm_fp;
int vm_fd;
static void incrRefCount(robj *o);
static int rdbSaveBackground(char *filename);
static robj *createStringObject(char *ptr, size_t len);
+static robj *dupStringObject(robj *o);
static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc);
static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc);
static int syncWithMaster(void);
static void vmInit(void);
static void vmMarkPagesFree(off_t page, off_t count);
static robj *vmLoadObject(robj *key);
+static int vmSwapOneObject(void);
static void authCommand(redisClient *c);
static void pingCommand(redisClient *c);
/* Continue to expire if at the end of the cycle more than 25%
* of the keys were expired. */
do {
- int num = dictSize(db->expires);
+ long num = dictSize(db->expires);
time_t now = time(NULL);
expired = 0;
} while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
}
+ /* Swap a few keys on disk if we are over the memory limit and VM
+ * is enbled. */
+ while (server.vm_enabled && zmalloc_used_memory() > server.vm_max_memory) {
+ if (vmSwapOneObject() == REDIS_ERR) {
+ redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit reached but unable to swap more objects out!");
+ break;
+ }
+ }
+
/* Check if we should connect to a MASTER */
if (server.replstate == REDIS_REPL_CONNECT) {
redisLog(REDIS_NOTICE,"Connecting to MASTER...");
if ((server.vm_enabled = yesnotoi(argv[1])) == -1) {
err = "argument must be 'yes' or 'no'"; goto loaderr;
}
+ } else if (!strcasecmp(argv[0],"vm-max-memory") && argc == 2) {
+ server.vm_max_memory = strtoll(argv[1], NULL, 10);
+ } else if (!strcasecmp(argv[0],"vm-page-size") && argc == 2) {
+ server.vm_page_size = strtoll(argv[1], NULL, 10);
+ } else if (!strcasecmp(argv[0],"vm-pages") && argc == 2) {
+ server.vm_pages = strtoll(argv[1], NULL, 10);
} else {
err = "Bad directive or wrong number of arguments"; goto loaderr;
}
return createObject(REDIS_STRING,sdsnewlen(ptr,len));
}
+static robj *dupStringObject(robj *o) {
+ return createStringObject(o->ptr,sdslen(o->ptr));
+}
+
static robj *createListObject(void) {
list *l = listCreate();
redisLog(REDIS_NOTICE,"Swap file allocated with success");
}
server.vm_bitmap = zmalloc((server.vm_pages+7)/8);
+ redisLog(REDIS_DEBUG,"Allocated %lld bytes page table for %lld pages",
+ (long long) (server.vm_pages+7)/8, server.vm_pages);
memset(server.vm_bitmap,0,(server.vm_pages+7)/8);
/* Try to remove the swap file, so the OS will really delete it from the
* file system when Redis exists. */
off_t byte = page/8;
int bit = page&7;
server.vm_bitmap[byte] |= 1<<bit;
- printf("Mark used: %lld (byte:%d bit:%d)\n", (long long)page, byte, bit);
+ printf("Mark used: %lld (byte:%lld bit:%d)\n", (long long)page,
+ (long long)byte, bit);
}
/* Mark N contiguous pages as used, with 'page' being the first. */
off_t page;
assert(key->storage == REDIS_VM_MEMORY);
+ assert(key->refcount == 1);
if (vmFindContiguousPages(&page,pages) == REDIS_ERR) return REDIS_ERR;
if (fseeko(server.vm_fp,page*server.vm_page_size,SEEK_SET) == -1) {
redisLog(REDIS_WARNING,
return val;
}
+/* How a good candidate is this object for swapping?
+ * The better candidate it is, the greater the returned value.
+ *
+ * Currently we try to perform a fast estimation of the object size in
+ * memory, and combine it with aging informations.
+ *
+ * Basically swappability = idle-time * log(estimated size)
+ *
+ * Bigger objects are preferred over smaller objects, but not
+ * proportionally, this is why we use the logarithm. This algorithm is
+ * just a first try and will probably be tuned later. */
+static double computeObjectSwappability(robj *o) {
+ time_t age = server.unixtime - o->vm.atime;
+ long asize = 0;
+ list *l;
+ dict *d;
+ struct dictEntry *de;
+ int z;
+
+ if (age <= 0) return 0;
+ switch(o->type) {
+ case REDIS_STRING:
+ if (o->encoding != REDIS_ENCODING_RAW) {
+ asize = sizeof(*o);
+ } else {
+ asize = sdslen(o->ptr)+sizeof(*o)+sizeof(long)*2;
+ }
+ break;
+ case REDIS_LIST:
+ l = o->ptr;
+ listNode *ln = listFirst(l);
+
+ asize = sizeof(list);
+ if (ln) {
+ robj *ele = ln->value;
+ long elesize;
+
+ elesize = (ele->encoding == REDIS_ENCODING_RAW) ?
+ (sizeof(*o)+sdslen(ele->ptr)) :
+ sizeof(*o);
+ asize += (sizeof(listNode)+elesize)*listLength(l);
+ }
+ break;
+ case REDIS_SET:
+ case REDIS_ZSET:
+ z = (o->type == REDIS_ZSET);
+ d = z ? ((zset*)o->ptr)->dict : o->ptr;
+
+ asize = sizeof(dict)+(sizeof(struct dictEntry*)*dictSlots(d));
+ if (z) asize += sizeof(zset)-sizeof(dict);
+ if (dictSize(d)) {
+ long elesize;
+ robj *ele;
+
+ de = dictGetRandomKey(d);
+ ele = dictGetEntryKey(de);
+ elesize = (ele->encoding == REDIS_ENCODING_RAW) ?
+ (sizeof(*o)+sdslen(ele->ptr)) :
+ sizeof(*o);
+ asize += (sizeof(struct dictEntry)+elesize)*dictSize(d);
+ if (z) asize += sizeof(zskiplistNode)*dictSize(d);
+ }
+ break;
+ }
+ return (double)asize*log(1+asize);
+}
+
+/* Try to swap an object that's a good candidate for swapping.
+ * Returns REDIS_OK if the object was swapped, REDIS_ERR if it's not possible
+ * to swap any object at all. */
+static int vmSwapOneObject(void) {
+ int j, i;
+ struct dictEntry *best = NULL;
+ double best_swappability = 0;
+ robj *key, *val;
+
+ for (j = 0; j < server.dbnum; j++) {
+ redisDb *db = server.db+j;
+
+ if (dictSize(db->dict) == 0) continue;
+ for (i = 0; i < 5; i++) {
+ dictEntry *de;
+ double swappability;
+
+ de = dictGetRandomKey(db->dict);
+ key = dictGetEntryKey(de);
+ val = dictGetEntryVal(de);
+ if (key->storage != REDIS_VM_MEMORY) continue;
+ swappability = computeObjectSwappability(val);
+ if (!best || swappability > best_swappability) {
+ best = de;
+ best_swappability = swappability;
+ }
+ }
+ }
+ if (best == NULL) return REDIS_ERR;
+ key = dictGetEntryKey(best);
+ val = dictGetEntryVal(best);
+
+ redisLog(REDIS_DEBUG,"Key with best swappability: %s, %f\n",
+ key->ptr, best_swappability);
+
+ /* Unshare the key if needed */
+ if (key->refcount > 1) {
+ robj *newkey = dupStringObject(key);
+ decrRefCount(key);
+ key = dictGetEntryKey(best) = newkey;
+ }
+ /* Swap it */
+ if (vmSwapObject(key,val) == REDIS_OK) {
+ dictGetEntryVal(best) = NULL;
+ return REDIS_OK;
+ } else {
+ return REDIS_ERR;
+ }
+}
+
/* ================================= Debugging ============================== */
static void debugCommand(redisClient *c) {
}
key = dictGetEntryKey(de);
val = dictGetEntryVal(de);
+ /* If the key is shared we want to create a copy */
+ if (key->refcount > 1) {
+ robj *newkey = dupStringObject(key);
+ decrRefCount(key);
+ key = dictGetEntryKey(de) = newkey;
+ }
+ /* Swap it */
if (key->storage != REDIS_VM_MEMORY) {
addReplySds(c,sdsnew("-ERR This key is not in memory\r\n"));
} else if (vmSwapObject(key,val) == REDIS_OK) {
################################ VIRTUAL MEMORY ###############################
+# Virtual Memory allows Redis to work with datasets bigger than the actual
+# amount of RAM needed to hold the whole dataset in memory.
+# In order to do so very used keys are taken in memory while the other keys
+# are swapped into a swap file, similarly to what operating systems do
+# with memory pages.
+#
+# To enable VM just set 'vm-enabled' to yes, and set the following three
+# VM parameters accordingly to your needs.
+
vm-enabled yes
+# vm-enabled no
+
+# vm-max-memory configures the VM to use at max the specified amount of
+# RAM. Everything that deos not fit will be swapped on disk *if* possible, that
+# is, if there is still enough contiguous space in the swap file.
+vm-max-memory 10000000
+
+# Redis swap files is split into pages. An object can be saved using multiple
+# contiguous pages, but pages can't be shared between different objects.
+# So if your page is too big, small objects swapped out on disk will waste
+# a lot of space. If you page is too small, there is less space in the swap
+# file (assuming you configured the same number of total swap file pages).
+#
+# If you use a lot of small objects, use a page size of 64 or 32 bytes.
+# If you use a lot of big objects, use a bigger page size.
+# If unsure, use the defualt :)
+vm-page-size 256
+
+# Number of total memory pages in the swap file.
+# Given that the page table (a bitmap of free/used pages) is taken in memory,
+# every 8 pages on disk will consume 1 byte of RAM.
+#
+# The total swap size is vm-page-size * vm-pages
+#
+# With the default of 256-bytes memory pages and 104857600 pages Redis will
+# use a 25 GB swap file, that will use rougly 13 MB of RAM for the page table.
+vm-pages 104857600
############################### ADVANCED CONFIG ###############################
{"call",(unsigned long)call},
{"closeTimedoutClients",(unsigned long)closeTimedoutClients},
{"compareStringObjects",(unsigned long)compareStringObjects},
+{"computeObjectSwappability",(unsigned long)computeObjectSwappability},
{"createClient",(unsigned long)createClient},
{"createListObject",(unsigned long)createListObject},
{"createObject",(unsigned long)createObject},
{"dictRedisObjectDestructor",(unsigned long)dictRedisObjectDestructor},
{"dictVanillaFree",(unsigned long)dictVanillaFree},
{"dupClientReplyValue",(unsigned long)dupClientReplyValue},
+{"dupStringObject",(unsigned long)dupStringObject},
{"echoCommand",(unsigned long)echoCommand},
{"execCommand",(unsigned long)execCommand},
{"existsCommand",(unsigned long)existsCommand},
{"rdbLoadIntegerObject",(unsigned long)rdbLoadIntegerObject},
{"rdbLoadLen",(unsigned long)rdbLoadLen},
{"rdbLoadLzfStringObject",(unsigned long)rdbLoadLzfStringObject},
+{"rdbLoadObject",(unsigned long)rdbLoadObject},
{"rdbLoadStringObject",(unsigned long)rdbLoadStringObject},
{"rdbLoadTime",(unsigned long)rdbLoadTime},
{"rdbLoadType",(unsigned long)rdbLoadType},
{"rdbSaveDoubleValue",(unsigned long)rdbSaveDoubleValue},
{"rdbSaveLen",(unsigned long)rdbSaveLen},
{"rdbSaveLzfStringObject",(unsigned long)rdbSaveLzfStringObject},
+{"rdbSaveObject",(unsigned long)rdbSaveObject},
{"rdbSaveStringObject",(unsigned long)rdbSaveStringObject},
{"rdbSaveStringObjectRaw",(unsigned long)rdbSaveStringObjectRaw},
{"rdbSaveTime",(unsigned long)rdbSaveTime},
{"rdbSaveType",(unsigned long)rdbSaveType},
+{"rdbSavedObjectLen",(unsigned long)rdbSavedObjectLen},
+{"rdbSavedObjectPages",(unsigned long)rdbSavedObjectPages},
{"rdbTryIntegerEncoding",(unsigned long)rdbTryIntegerEncoding},
{"readQueryFromClient",(unsigned long)readQueryFromClient},
{"redisLog",(unsigned long)redisLog},
{"typeCommand",(unsigned long)typeCommand},
{"unblockClient",(unsigned long)unblockClient},
{"updateSlavesWaitingBgsave",(unsigned long)updateSlavesWaitingBgsave},
+{"vmFindContiguousPages",(unsigned long)vmFindContiguousPages},
+{"vmFreePage",(unsigned long)vmFreePage},
+{"vmInit",(unsigned long)vmInit},
+{"vmLoadObject",(unsigned long)vmLoadObject},
+{"vmMarkPageFree",(unsigned long)vmMarkPageFree},
+{"vmMarkPageUsed",(unsigned long)vmMarkPageUsed},
+{"vmMarkPagesFree",(unsigned long)vmMarkPagesFree},
+{"vmMarkPagesUsed",(unsigned long)vmMarkPagesUsed},
+{"vmSwapObject",(unsigned long)vmSwapObject},
+{"vmSwapOneObject",(unsigned long)vmSwapOneObject},
{"yesnotoi",(unsigned long)yesnotoi},
{"zaddCommand",(unsigned long)zaddCommand},
{"zaddGenericCommand",(unsigned long)zaddGenericCommand},
projects / redis.git / commitdiff
