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以下涉及到的源码均为redis5.0-rc3版本的代码【点击查看官方源码】
文章目录
服务器结构
在redis的头文件server.h中定义了服务器的数据结构，略见如下：（详细的可在文末的源码部分见得）
struct redisServer {
//服务器的一些信息
·
·
·
}
服务器初始化
在redis服务器启动中，在服务器的初始化过程中主要由三个函数操作：
- initServerConfig：先初始相关配置
- initServer：接着初始化服务器
- serverCron：再让服务器在后台做一些定时任务操作
- 其他的一些初始化操作
而这三个过程中，基本的初始化配置就不需要再说明了，可见后面源码；接下来介绍了以下serverCron函数以及其中的databasesCron函数。
serverCron函数
serverCron函数中的操作是再服务器背后定期运行的，做了一些重要的操作，比如：过期键的删除、设备软件的监控、静态变量的更新、rehash、BGSAVE/AOF的重写等等操作。具体详见函数源码：
/* This is our timer interrupt, called server.hz times per second.
* Here is where we do a number of things that need to be done asynchronously.
* For instance:
*
* - Active expired keys collection (it is also performed in a lazy way on
* lookup).
* - Software watchdog.
* - Update some statistic.
* - Incremental rehashing of the DBs hash tables.
* - Triggering BGSAVE / AOF rewrite, and handling of terminated children.
* - Clients timeout of different kinds.
* - Replication reconnection.
* - Many more...
*
* Everything directly called here will be called server.hz times per second,
* so in order to throttle execution of things we want to do less frequently
* a macro is used: run_with_period(milliseconds) { .... }
*/
int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
int j;
UNUSED(eventLoop);
UNUSED(id);
UNUSED(clientData);
/* Software watchdog: deliver the SIGALRM that will reach the signal
* handler if we don't return here fast enough. */
if (server.watchdog_period) watchdogScheduleSignal(server.watchdog_period);
//更新时间缓存
updateCachedTime();
//每100毫秒运行一次
run_with_period(100) {
trackInstantaneousMetric(STATS_METRIC_COMMAND,server.stat_numcommands);
trackInstantaneousMetric(STATS_METRIC_NET_INPUT,
server.stat_net_input_bytes);
trackInstantaneousMetric(STATS_METRIC_NET_OUTPUT,
server.stat_net_output_bytes);
}
/* We have just LRU_BITS bits per object for LRU information.
* So we use an (eventually wrapping) LRU clock.
*
* Note that even if the counter wraps it's not a big problem,
* everything will still work but some object will appear younger
* to Redis. However for this to happen a given object should never be
* touched for all the time needed to the counter to wrap, which is
* not likely.
*
* Note that you can change the resolution altering the
* LRU_CLOCK_RESOLUTION define. */
unsigned long lruclock = getLRUClock();
atomicSet(server.lruclock,lruclock);
记录自服务器启动以来的已使用的内存
if (zmalloc_used_memory() > server.stat_peak_memory)
server.stat_peak_memory = zmalloc_used_memory();
//每100毫秒运行一次
run_with_period(100) {
/* Sample the RSS and other metrics here since this is a relatively slow call.
* We must sample the zmalloc_used at the same time we take the rss, otherwise
* the frag ratio calculate may be off (ratio of two samples at different times) */
server.cron_malloc_stats.process_rss = zmalloc_get_rss();
server.cron_malloc_stats.zmalloc_used = zmalloc_used_memory();
/* Sampling the allcator info can be slow too.
* The fragmentation ratio it'll show is potentically more accurate
* it excludes other RSS pages such as: shared libraries, LUA and other non-zmalloc
* allocations, and allocator reserved pages that can be pursed (all not actual frag) */
zmalloc_get_allocator_info(&server.cron_malloc_stats.allocator_allocated,
&server.cron_malloc_stats.allocator_active,
&server.cron_malloc_stats.allocator_resident);
/* in case the allocator isn't providing these stats, fake them so that
* fragmention info still shows some (inaccurate metrics) */
if (!server.cron_malloc_stats.allocator_resident) {
/* LUA memory isn't part of zmalloc_used, but it is part of the process RSS,
* so we must desuct it in order to be able to calculate correct
* "allocator fragmentation" ratio */
size_t lua_memory = lua_gc(server.lua,LUA_GCCOUNT,0)*1024LL;
server.cron_malloc_stats.allocator_resident = server.cron_malloc_stats.process_rss - lua_memory;
}
if (!server.cron_malloc_stats.allocator_active)
server.cron_malloc_stats.allocator_active = server.cron_malloc_stats.allocator_resident;
if (!server.cron_malloc_stats.allocator_allocated)
server.cron_malloc_stats.allocator_allocated = server.cron_malloc_stats.zmalloc_used;
}
//接收一个SIGTERM信好去安全的关闭服务（避免出现不安全操作）
if (server.shutdown_asap) {
if (prepareForShutdown(SHUTDOWN_NOFLAGS) == C_OK) exit(0);
serverLog(LL_WARNING,"SIGTERM received but errors trying to shut down the server, check the logs for more information");
server.shutdown_asap = 0;
}
//展示非空数据库的信息
run_with_period(5000) {
for (j = 0; j < server.dbnum; j++) {
long long size, used, vkeys;
size = dictSlots(server.db[j].dict);
used = dictSize(server.db[j].dict);
vkeys = dictSize(server.db[j].expires);
if (used || vkeys) {
serverLog(LL_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
/* dictPrintStats(server.dict); */
}
}
}
//展示连接的客户端的信息
if (!server.sentinel_mode) {
run_with_period(5000) {
serverLog(LL_VERBOSE,
"%lu clients connected (%lu slaves), %zu bytes in use",
listLength(server.clients)-listLength(server.slaves),
listLength(server.slaves),
zmalloc_used_memory());
}
}
//客户端的一些异步操作
clientsCron();
//后台对database的一些运行操作
databasesCron();
//aop重写操作
if (server.rdb_child_pid == -1 && server.aof_child_pid == -1 &&
server.aof_rewrite_scheduled)
{
rewriteAppendOnlyFileBackground();
}
//检查是否有在后台运行rdbsava和aop重写操作
if (server.rdb_child_pid != -1 || server.aof_child_pid != -1 ||
ldbPendingChildren())
{
int statloc;
pid_t pid;
if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
int exitcode = WEXITSTATUS(statloc);
int bysignal = 0;
if (WIFSIGNALED(statloc)) bysignal = WTERMSIG(statloc);
if (pid == -1) {
serverLog(LL_WARNING,"wait3() returned an error: %s. "
"rdb_child_pid = %d, aof_child_pid = %d",
strerror(errno),
(int) server.rdb_child_pid,
(int) server.aof_child_pid);
} else if (pid == server.rdb_child_pid) {
backgroundSaveDoneHandler(exitcode,bysignal);
if (!bysignal && exitcode == 0) receiveChildInfo();
} else if (pid == server.aof_child_pid) {
backgroundRewriteDoneHandler(exitcode,bysignal);
if (!bysignal && exitcode == 0) receiveChildInfo();
} else {
if (!ldbRemoveChild(pid)) {
serverLog(LL_WARNING,
"Warning, detected child with unmatched pid: %ld",
(long)pid);
}
}
updateDictResizePolicy();
closeChildInfoPipe();
}
} else {
/* If there is not a background saving/rewrite in progress check if
* we have to save/rewrite now. */
for (j = 0; j < server.saveparamslen; j++) {
struct saveparam *sp = server.saveparams+j;
/* Save if we reached the given amount of changes,
* the given amount of seconds, and if the latest bgsave was
* successful or if, in case of an error, at least
* CONFIG_BGSAVE_RETRY_DELAY seconds already elapsed. */
if (server.dirty >= sp->changes &&
server.unixtime-server.lastsave > sp->seconds &&
(server.unixtime-server.lastbgsave_try >
CONFIG_BGSAVE_RETRY_DELAY ||
server.lastbgsave_status == C_OK))
{
serverLog(LL_NOTICE,"%d changes in %d seconds. Saving...",
sp->changes, (int)sp->seconds);
rdbSaveInfo rsi, *rsiptr;
rsiptr = rdbPopulateSaveInfo(&rsi);
rdbSaveBackground(server.rdb_filename,rsiptr);
break;
}
}
//在条件满足的情况下触发aof重写操作
if (server.aof_state == AOF_ON &&
server.rdb_child_pid == -1 &&
server.aof_child_pid == -1 &&
server.aof_rewrite_perc &&
server.aof_current_size > server.aof_rewrite_min_size)
{
long long base = server.aof_rewrite_base_size ?
server.aof_rewrite_base_size : 1;
long long growth = (server.aof_current_size*100/base) - 100;
if (growth >= server.aof_rewrite_perc) {
serverLog(LL_NOTICE,"Starting automatic rewriting of AOF on %lld%% growth",growth);
rewriteAppendOnlyFileBackground();
}
}
}
//如果之前的执行周期还未完成，则延迟清楚buffer
if (server.aof_flush_postponed_start) flushAppendOnlyFile(0);
/* AOF write errors: in this case we have a buffer to flush as well and
* clear the AOF error in case of success to make the DB writable again,
* however to try every second is enough in case of 'hz' is set to
* an higher frequency. */
run_with_period(1000) {
if (server.aof_last_write_status == C_ERR)
flushAppendOnlyFile(0);
}
//释放客户端
freeClientsInAsyncFreeQueue();
//清楚已暂停使用的客户端
clientsArePaused();
/* Replication cron function -- used to reconnect to master,
* detect transfer failures, start background RDB transfers and so forth. */
run_with_period(1000) replicationCron();
run_with_period(100) {
//如果是集群模式，则每100毫秒执行一次集群模式下相关的事件
if (server.cluster_enabled) clusterCron();
}
run_with_period(100) {
//如果sentinel模式存在，则没100毫秒执行一次哨兵模式下的一些事件
if (server.sentinel_mode) sentinelTimer();
}
run_with_period(1000) {
//每秒清理一次废弃的sockets链接
migrateCloseTimedoutSockets();
}
/* Start a scheduled BGSAVE if the corresponding flag is set. This is
* useful when we are forced to postpone a BGSAVE because an AOF
* rewrite is in progress.
*
* Note: this code must be after the replicationCron() call above so
* make sure when refactoring this file to keep this order. This is useful
* because we want to give priority to RDB savings for replication. */
if (server.rdb_child_pid == -1 && server.aof_child_pid == -1 &&
server.rdb_bgsave_scheduled &&
(server.unixtime-server.lastbgsave_try > CONFIG_BGSAVE_RETRY_DELAY ||
server.lastbgsave_status == C_OK))
{
rdbSaveInfo rsi, *rsiptr;
rsiptr = rdbPopulateSaveInfo(&rsi);
if (rdbSaveBackground(server.rdb_filename,rsiptr) == C_OK)
server.rdb_bgsave_scheduled = 0;
}
server.cronloops++;
return 1000/server.hz;
}
databasesCron
databasesCron是serverCron中的一个子函数，其执行时间为每100ms执行一次。主要的功能是去执行一些数据库的增量操作，比如键的过期，空间的resizing和hash表的rehashing操作等。
/* This function handles 'background' operations we are required to do
* incrementally in Redis databases, such as active key expiring, resizing,
* rehashing. */
void databasesCron(void) {
/* Expire keys by random sampling. Not required for slaves
* as master will synthesize DELs for us. */
if (server.active_expire_enabled && server.masterhost == NULL) {
activeExpireCycle(ACTIVE_EXPIRE_CYCLE_SLOW);
} else if (server.masterhost != NULL) {
expireSlaveKeys();
}
/* Defrag keys gradually. */
if (server.active_defrag_enabled)
activeDefragCycle();
/* Perform hash tables rehashing if needed, but only if there are no
* other processes saving the DB on disk. Otherwise rehashing is bad
* as will cause a lot of copy-on-write of memory pages. */
if (server.rdb_child_pid == -1 && server.aof_child_pid == -1) {
/* We use global counters so if we stop the computation at a given
* DB we'll be able to start from the successive in the next
* cron loop iteration. */
static unsigned int resize_db = 0;
static unsigned int rehash_db = 0;
int dbs_per_call = CRON_DBS_PER_CALL; //server.h中宏定义 #define CRON_DBS_PER_CALL 16
int j;
/* Don't test more DBs than we have. */
if (dbs_per_call > server.dbnum) dbs_per_call = server.dbnum;
/* Resize */
for (j = 0; j < dbs_per_call; j++) {
tryResizeHashTables(resize_db % server.dbnum);
resize_db++;
}
/* Rehash */
if (server.activerehashing) {
for (j = 0; j < dbs_per_call; j++) {
int work_done = incrementallyRehash(rehash_db);
if (work_done) {
/* If the function did some work, stop here, we'll do
* more at the next cron loop. */
break;
} else {
/* If this db didn't need rehash, we'll try the next one. */
rehash_db++;
rehash_db %= server.dbnum;
}
}
}
}
}
/* Our hash table implementation performs rehashing incrementally while
* we write/read from the hash table. Still if the server is idle, the hash
* table will use two tables for a long time. So we try to use 1 millisecond
* of CPU time at every call of this function to perform some rehahsing.
*
* The function returns 1 if some rehashing was performed, otherwise 0
* is returned. */
int incrementallyRehash(int dbid) {
/* Keys dictionary */
if (dictIsRehashing(server.db[dbid].dict)) {
dictRehashMilliseconds(server.db[dbid].dict,1);
return 1; /* already used our millisecond for this loop... */
}
/* Expires */
if (dictIsRehashing(server.db[dbid].expires)) {
dictRehashMilliseconds(server.db[dbid].expires,1);
return 1; /* already used our millisecond for this loop... */
}
return 0;
}
redisServer/initServerConfig/initServer源码
这里贴身三个函数的源码，更详细的服务器启动初始化详见源码中的server.c文件。
redisServer
struct redisServer {
/* General */
pid_t pid; /* Main process pid. */
char *configfile; /* Absolute config file path, or NULL */
char *executable; /* Absolute executable file path. */
char **exec_argv; /* Executable argv vector (copy). */
int hz; /* serverCron() calls frequency in hertz */
redisDb *db;
dict *commands; /* Command table */
dict *orig_commands; /* Command table before command renaming. */
aeEventLoop *el;
unsigned int lruclock; /* Clock for LRU eviction */
int shutdown_asap; /* SHUTDOWN needed ASAP */
int activerehashing; /* Incremental rehash in serverCron() */
int active_defrag_running; /* Active defragmentation running (holds current scan aggressiveness) */
char *requirepass; /* Pass for AUTH command, or NULL */
char *pidfile; /* PID file path */
int arch_bits; /* 32 or 64 depending on sizeof(long) */
int cronloops; /* Number of times the cron function run */
char runid[CONFIG_RUN_ID_SIZE+1]; /* ID always different at every exec. */
int sentinel_mode; /* True if this instance is a Sentinel. */
size_t initial_memory_usage; /* Bytes used after initialization. */
int always_show_logo; /* Show logo even for non-stdout logging. */
/* Modules */
dict *moduleapi; /* Exported APIs dictionary for modules. */
list *loadmodule_queue; /* List of modules to load at startup. */
int module_blocked_pipe[2]; /* Pipe used to awake the event loop if a
client blocked on a module command needs
to be processed. */
/* Networking */
int port; /* TCP listening port */
int tcp_backlog; /* TCP listen() backlog */
char *bindaddr[CONFIG_BINDADDR_MAX]; /* Addresses we should bind to */
int bindaddr_count; /* Number of addresses in server.bindaddr[] */
char *unixsocket; /* UNIX socket path */
mode_t unixsocketperm; /* UNIX socket permission */
int ipfd[CONFIG_BINDADDR_MAX]; /* TCP socket file descriptors */
int ipfd_count; /* Used slots in ipfd[] */
int sofd; /* Unix socket file descriptor */
int cfd[CONFIG_BINDADDR_MAX];/* Cluster bus listening socket */
int cfd_count; /* Used slots in cfd[] */
list *clients; /* List of active clients */
list *clients_to_close; /* Clients to close asynchronously */
list *clients_pending_write; /* There is to write or install handler. */
list *slaves, *monitors; /* List of slaves and MONITORs */
client *current_client; /* Current client, only used on crash report */
int clients_paused; /* True if clients are currently paused */
mstime_t clients_pause_end_time; /* Time when we undo clients_paused */
char neterr[ANET_ERR_LEN]; /* Error buffer for anet.c */
dict *migrate_cached_sockets;/* MIGRATE cached sockets */
uint64_t next_client_id; /* Next client unique ID. Incremental. */
int protected_mode; /* Don't accept external connections. */
/* RDB / AOF loading information */
int loading; /* We are loading data from disk if true */
off_t loading_total_bytes;
off_t loading_loaded_bytes;
time_t loading_start_time;
off_t loading_process_events_interval_bytes;
/* Fast pointers to often looked up command */
struct redisCommand *delCommand, *multiCommand, *lpushCommand,
*lpopCommand, *rpopCommand, *zpopminCommand,
*zpopmaxCommand, *sremCommand, *execCommand,
*expireCommand, *pexpireCommand, *xclaimCommand;
/* Fields used only for stats */
time_t stat_starttime; /* Server start time */
long long stat_numcommands; /* Number of processed commands */
long long stat_numconnections; /* Number of connections received */
long long stat_expiredkeys; /* Number of expired keys */
double stat_expired_stale_perc; /* Percentage of keys probably expired */
long long stat_expired_time_cap_reached_count; /* Early expire cylce stops.*/
long long stat_evictedkeys; /* Number of evicted keys (maxmemory) */
long long stat_keyspace_hits; /* Number of successful lookups of keys */
long long stat_keyspace_misses; /* Number of failed lookups of keys */
long long stat_active_defrag_hits; /* number of allocations moved */
long long stat_active_defrag_misses; /* number of allocations scanned but not moved */
long long stat_active_defrag_key_hits; /* number of keys with moved allocations */
long long stat_active_defrag_key_misses;/* number of keys scanned and not moved */
long long stat_active_defrag_scanned; /* number of dictEntries scanned */
size_t stat_peak_memory; /* Max used memory record */
long long stat_fork_time; /* Time needed to perform latest fork() */
double stat_fork_rate; /* Fork rate in GB/sec. */
long long stat_rejected_conn; /* Clients rejected because of maxclients */
long long stat_sync_full; /* Number of full resyncs with slaves. */
long long stat_sync_partial_ok; /* Number of accepted PSYNC requests. */
long long stat_sync_partial_err;/* Number of unaccepted PSYNC requests. */
list *slowlog; /* SLOWLOG list of commands */
long long slowlog_entry_id; /* SLOWLOG current entry ID */
long long slowlog_log_slower_than; /* SLOWLOG time limit (to get logged) */
unsigned long slowlog_max_len; /* SLOWLOG max number of items logged */
malloc_stats cron_malloc_stats; /* sampled in serverCron(). */
long long stat_net_input_bytes; /* Bytes read from network. */
long long stat_net_output_bytes; /* Bytes written to network. */
size_t stat_rdb_cow_bytes; /* Copy on write bytes during RDB saving. */
size_t stat_aof_cow_bytes; /* Copy on write bytes during AOF rewrite. */
/* The following two are used to track instantaneous metrics, like
* number of operations per second, network traffic. */
struct {
long long last_sample_time; /* Timestamp of last sample in ms */
long long last_sample_count;/* Count in last sample */
long long samples[STATS_METRIC_SAMPLES];
int idx;
} inst_metric[STATS_METRIC_COUNT];
/* Configuration */
int verbosity; /* Loglevel in redis.conf */
int maxidletime; /* Client timeout in seconds */
int tcpkeepalive; /* Set SO_KEEPALIVE if non-zero. */
int active_expire_enabled; /* Can be disabled for testing purposes. */
int active_defrag_enabled;
size_t active_defrag_ignore_bytes; /* minimum amount of fragmentation waste to start active defrag */
int active_defrag_threshold_lower; /* minimum percentage of fragmentation to start active defrag */
int active_defrag_threshold_upper; /* maximum percentage of fragmentation at which we use maximum effort */
int active_defrag_cycle_min; /* minimal effort for defrag in CPU percentage */
int active_defrag_cycle_max; /* maximal effort for defrag in CPU percentage */
unsigned long active_defrag_max_scan_fields; /* maximum number of fields of set/hash/zset/list to process from within the main dict scan */
size_t client_max_querybuf_len; /* Limit for client query buffer length */
int dbnum; /* Total number of configured DBs */
int supervised; /* 1 if supervised, 0 otherwise. */
int supervised_mode; /* See SUPERVISED_* */
int daemonize; /* True if running as a daemon */
clientBufferLimitsConfig client_obuf_limits[CLIENT_TYPE_OBUF_COUNT];
/* AOF persistence */
int aof_state; /* AOF_(ON|OFF|WAIT_REWRITE) */
int aof_fsync; /* Kind of fsync() policy */
char *aof_filename; /* Name of the AOF file */
int aof_no_fsync_on_rewrite; /* Don't fsync if a rewrite is in prog. */
int aof_rewrite_perc; /* Rewrite AOF if % growth is > M and... */
off_t aof_rewrite_min_size; /* the AOF file is at least N bytes. */
off_t aof_rewrite_base_size; /* AOF size on latest startup or rewrite. */
off_t aof_current_size; /* AOF current size. */
int aof_rewrite_scheduled; /* Rewrite once BGSAVE terminates. */
pid_t aof_child_pid; /* PID if rewriting process */
list *aof_rewrite_buf_blocks; /* Hold changes during an AOF rewrite. */
sds aof_buf; /* AOF buffer, written before entering the event loop */
int aof_fd; /* File descriptor of currently selected AOF file */
int aof_selected_db; /* Currently selected DB in AOF */
time_t aof_flush_postponed_start; /* UNIX time of postponed AOF flush */
time_t aof_last_fsync; /* UNIX time of last fsync() */
time_t aof_rewrite_time_last; /* Time used by last AOF rewrite run. */
time_t aof_rewrite_time_start; /* Current AOF rewrite start time. */
int aof_lastbgrewrite_status; /* C_OK or C_ERR */
unsigned long aof_delayed_fsync; /* delayed AOF fsync() counter */
int aof_rewrite_incremental_fsync;/* fsync incrementally while rewriting? */
int aof_last_write_status; /* C_OK or C_ERR */
int aof_last_write_errno; /* Valid if aof_last_write_status is ERR */
int aof_load_truncated; /* Don't stop on unexpected AOF EOF. */
int aof_use_rdb_preamble; /* Use RDB preamble on AOF rewrites. */
/* AOF pipes used to communicate between parent and child during rewrite. */
int aof_pipe_write_data_to_child;
int aof_pipe_read_data_from_parent;
int aof_pipe_write_ack_to_parent;
int aof_pipe_read_ack_from_child;
int aof_pipe_write_ack_to_child;
int aof_pipe_read_ack_from_parent;
int aof_stop_sending_diff; /* If true stop sending accumulated diffs
to child process. */
sds aof_child_diff; /* AOF diff accumulator child side. */
/* RDB persistence */
long long dirty; /* Changes to DB from the last save */
long long dirty_before_bgsave; /* Used to restore dirty on failed BGSAVE */
pid_t rdb_child_pid; /* PID of RDB saving child */
struct saveparam *saveparams; /* Save points array for RDB */
int saveparamslen; /* Number of saving points */
char *rdb_filename; /* Name of RDB file */
int rdb_compression; /* Use compression in RDB? */
int rdb_checksum; /* Use RDB checksum? */
time_t lastsave; /* Unix time of last successful save */
time_t lastbgsave_try; /* Unix time of last attempted bgsave */
time_t rdb_save_time_last; /* Time used by last RDB save run. */
time_t rdb_save_time_start; /* Current RDB save start time. */
int rdb_bgsave_scheduled; /* BGSAVE when possible if true. */
int rdb_child_type; /* Type of save by active child. */
int lastbgsave_status; /* C_OK or C_ERR */
int stop_writes_on_bgsave_err; /* Don't allow writes if can't BGSAVE */
int rdb_pipe_write_result_to_parent; /* RDB pipes used to return the state */
int rdb_pipe_read_result_from_child; /* of each slave in diskless SYNC. */
/* Pipe and data structures for child -> parent info sharing. */
int child_info_pipe[2]; /* Pipe used to write the child_info_data. */
struct {
int process_type; /* AOF or RDB child? */
size_t cow_size; /* Copy on write size. */
unsigned long long magic; /* Magic value to make sure data is valid. */
} child_info_data;
/* Propagation of commands in AOF / replication */
redisOpArray also_propagate; /* Additional command to propagate. */
/* Logging */
char *logfile; /* Path of log file */
int syslog_enabled; /* Is syslog enabled? */
char *syslog_ident; /* Syslog ident */
int syslog_facility; /* Syslog facility */
/* Replication (master) */
char replid[CONFIG_RUN_ID_SIZE+1]; /* My current replication ID. */
char replid2[CONFIG_RUN_ID_SIZE+1]; /* replid inherited from master*/
long long master_repl_offset; /* My current replication offset */
long long second_replid_offset; /* Accept offsets up to this for replid2. */
int slaveseldb; /* Last SELECTed DB in replication output */
int repl_ping_slave_period; /* Master pings the slave every N seconds */
char *repl_backlog; /* Replication backlog for partial syncs */
long long repl_backlog_size; /* Backlog circular buffer size */
long long repl_backlog_histlen; /* Backlog actual data length */
long long repl_backlog_idx; /* Backlog circular buffer current offset,
that is the next byte will'll write to.*/
long long repl_backlog_off; /* Replication "master offset" of first
byte in the replication backlog buffer.*/
time_t repl_backlog_time_limit; /* Time without slaves after the backlog
gets released. */
time_t repl_no_slaves_since; /* We have no slaves since that time.
Only valid if server.slaves len is 0. */
int repl_min_slaves_to_write; /* Min number of slaves to write. */
int repl_min_slaves_max_lag; /* Max lag of <count> slaves to write. */
int repl_good_slaves_count; /* Number of slaves with lag <= max_lag. */
int repl_diskless_sync; /* Send RDB to slaves sockets directly. */
int repl_diskless_sync_delay; /* Delay to start a diskless repl BGSAVE. */
/* Replication (slave) */
char *masterauth; /* AUTH with this password with master */
char *masterhost; /* Hostname of master */
int masterport; /* Port of master */
int repl_timeout; /* Timeout after N seconds of master idle */
client *master; /* Client that is master for this slave */
client *cached_master; /* Cached master to be reused for PSYNC. */
int repl_syncio_timeout; /* Timeout for synchronous I/O calls */
int repl_state; /* Replication status if the instance is a slave */
off_t repl_transfer_size; /* Size of RDB to read from master during sync. */
off_t repl_transfer_read; /* Amount of RDB read from master during sync. */
off_t repl_transfer_last_fsync_off; /* Offset when we fsync-ed last time. */
int repl_transfer_s; /* Slave -> Master SYNC socket */
int repl_transfer_fd; /* Slave -> Master SYNC temp file descriptor */
char *repl_transfer_tmpfile; /* Slave-> master SYNC temp file name */
time_t repl_transfer_lastio; /* Unix time of the latest read, for timeout */
int repl_serve_stale_data; /* Serve stale data when link is down? */
int repl_slave_ro; /* Slave is read only? */
time_t repl_down_since; /* Unix time at which link with master went down */
int repl_disable_tcp_nodelay; /* Disable TCP_NODELAY after SYNC? */
int slave_priority; /* Reported in INFO and used by Sentinel. */
int slave_announce_port; /* Give the master this listening port. */
char *slave_announce_ip; /* Give the master this ip address. */
/* The following two fields is where we store master PSYNC replid/offset
* while the PSYNC is in progress. At the end we'll copy the fields into
* the server->master client structure. */
char master_replid[CONFIG_RUN_ID_SIZE+1]; /* Master PSYNC runid. */
long long master_initial_offset; /* Master PSYNC offset. */
int repl_slave_lazy_flush; /* Lazy FLUSHALL before loading DB? */
/* Replication script cache. */
dict *repl_scriptcache_dict; /* SHA1 all slaves are aware of. */
list *repl_scriptcache_fifo; /* First in, first out LRU eviction. */
unsigned int repl_scriptcache_size; /* Max number of elements. */
/* Synchronous replication. */
list *clients_waiting_acks; /* Clients waiting in WAIT command. */
int get_ack_from_slaves; /* If true we send REPLCONF GETACK. */
/* Limits */
unsigned int maxclients; /* Max number of simultaneous clients */
unsigned long long maxmemory; /* Max number of memory bytes to use */
int maxmemory_policy; /* Policy for key eviction */
int maxmemory_samples; /* Pricision of random sampling */
int lfu_log_factor; /* LFU logarithmic counter factor. */
int lfu_decay_time; /* LFU counter decay factor. */
long long proto_max_bulk_len; /* Protocol bulk length maximum size. */
/* Blocked clients */
unsigned int blocked_clients; /* # of clients executing a blocking cmd.*/
unsigned int blocked_clients_by_type[BLOCKED_NUM];
list *unblocked_clients; /* list of clients to unblock before next loop */
list *ready_keys; /* List of readyList structures for BLPOP & co */
/* 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;
int sort_alpha;
int sort_bypattern;
int sort_store;
/* Zip structure config, see redis.conf for more information */
size_t hash_max_ziplist_entries;
size_t hash_max_ziplist_value;
size_t set_max_intset_entries;
size_t zset_max_ziplist_entries;
size_t zset_max_ziplist_value;
size_t hll_sparse_max_bytes;
size_t stream_node_max_bytes;
int64_t stream_node_max_entries;
/* List parameters */
int list_max_ziplist_size;
int list_compress_depth;
/* time cache */
time_t unixtime; /* Unix time sampled every cron cycle. */
long long mstime; /* Like 'unixtime' but with milliseconds resolution. */
/* Pubsub */
dict *pubsub_channels; /* Map channels to list of subscribed clients */
list *pubsub_patterns; /* A list of pubsub_patterns */
int notify_keyspace_events; /* Events to propagate via Pub/Sub. This is an
xor of NOTIFY_... flags. */
/* Cluster */
int cluster_enabled; /* Is cluster enabled? */
mstime_t cluster_node_timeout; /* Cluster node timeout. */
char *cluster_configfile; /* Cluster auto-generated config file name. */
struct clusterState *cluster; /* State of the cluster */
int cluster_migration_barrier; /* Cluster replicas migration barrier. */
int cluster_slave_validity_factor; /* Slave max data age for failover. */
int cluster_require_full_coverage; /* If true, put the cluster down if
there is at least an uncovered slot.*/
int cluster_slave_no_failover; /* Prevent slave from starting a failover
if the master is in failure state. */
char *cluster_announce_ip; /* IP address to announce on cluster bus. */
int cluster_announce_port; /* base port to announce on cluster bus. */
int cluster_announce_bus_port; /* bus port to announce on cluster bus. */
/* Scripting */
lua_State *lua; /* The Lua interpreter. We use just one for all clients */
client *lua_client; /* The "fake client" to query Redis from Lua */
client *lua_caller; /* The client running EVAL right now, or NULL */
dict *lua_scripts; /* A dictionary of SHA1 -> Lua scripts */
mstime_t lua_time_limit; /* Script timeout in milliseconds */
mstime_t lua_time_start; /* Start time of script, milliseconds time */
int lua_write_dirty; /* True if a write command was called during the
execution of the current script. */
int lua_random_dirty; /* True if a random command was called during the
execution of the current script. */
int lua_replicate_commands; /* True if we are doing single commands repl. */
int lua_multi_emitted;/* True if we already proagated MULTI. */
int lua_repl; /* Script replication flags for redis.set_repl(). */
int lua_timedout; /* True if we reached the time limit for script
execution. */
int lua_kill; /* Kill the script if true. */
int lua_always_replicate_commands; /* Default replication type. */
/* Lazy free */
int lazyfree_lazy_eviction;
int lazyfree_lazy_expire;
int lazyfree_lazy_server_del;
/* Latency monitor */
long long latency_monitor_threshold;
dict *latency_events;
/* Assert & bug reporting */
const char *assert_failed;
const char *assert_file;
int assert_line;
int bug_report_start; /* True if bug report header was already logged. */
int watchdog_period; /* Software watchdog period in ms. 0 = off */
/* System hardware info */
size_t system_memory_size; /* Total memory in system as reported by OS */
/* Mutexes used to protect atomic variables when atomic builtins are
* not available. */
pthread_mutex_t lruclock_mutex;
pthread_mutex_t next_client_id_mutex;
pthread_mutex_t unixtime_mutex;
};
initServerConfig
void initServerConfig(void) {
int j;
pthread_mutex_init(&server.next_client_id_mutex,NULL);
pthread_mutex_init(&server.lruclock_mutex,NULL);
pthread_mutex_init(&server.unixtime_mutex,NULL);
getRandomHexChars(server.runid,CONFIG_RUN_ID_SIZE);
server.runid[CONFIG_RUN_ID_SIZE] = '\0';
changeReplicationId();
clearReplicationId2();
server.configfile = NULL;
server.executable = NULL;
server.hz = CONFIG_DEFAULT_HZ;
server.arch_bits = (sizeof(long) == 8) ? 64 : 32;
server.port = CONFIG_DEFAULT_SERVER_PORT;
server.tcp_backlog = CONFIG_DEFAULT_TCP_BACKLOG;
server.bindaddr_count = 0;
server.unixsocket = NULL;
server.unixsocketperm = CONFIG_DEFAULT_UNIX_SOCKET_PERM;
server.ipfd_count = 0;
server.sofd = -1;
server.protected_mode = CONFIG_DEFAULT_PROTECTED_MODE;
server.dbnum = CONFIG_DEFAULT_DBNUM;
server.verbosity = CONFIG_DEFAULT_VERBOSITY;
server.maxidletime = CONFIG_DEFAULT_CLIENT_TIMEOUT;
server.tcpkeepalive = CONFIG_DEFAULT_TCP_KEEPALIVE;
server.active_expire_enabled = 1;
server.active_defrag_enabled = CONFIG_DEFAULT_ACTIVE_DEFRAG;
server.active_defrag_ignore_bytes = CONFIG_DEFAULT_DEFRAG_IGNORE_BYTES;
server.active_defrag_threshold_lower = CONFIG_DEFAULT_DEFRAG_THRESHOLD_LOWER;
server.active_defrag_threshold_upper = CONFIG_DEFAULT_DEFRAG_THRESHOLD_UPPER;
server.active_defrag_cycle_min = CONFIG_DEFAULT_DEFRAG_CYCLE_MIN;
server.active_defrag_cycle_max = CONFIG_DEFAULT_DEFRAG_CYCLE_MAX;
server.active_defrag_max_scan_fields = CONFIG_DEFAULT_DEFRAG_MAX_SCAN_FIELDS;
server.proto_max_bulk_len = CONFIG_DEFAULT_PROTO_MAX_BULK_LEN;
server.client_max_querybuf_len = PROTO_MAX_QUERYBUF_LEN;
server.saveparams = NULL;
server.loading = 0;
server.logfile = zstrdup(CONFIG_DEFAULT_LOGFILE);
server.syslog_enabled = CONFIG_DEFAULT_SYSLOG_ENABLED;
server.syslog_ident = zstrdup(CONFIG_DEFAULT_SYSLOG_IDENT);
server.syslog_facility = LOG_LOCAL0;
server.daemonize = CONFIG_DEFAULT_DAEMONIZE;
server.supervised = 0;
server.supervised_mode = SUPERVISED_NONE;
server.aof_state = AOF_OFF;
server.aof_fsync = CONFIG_DEFAULT_AOF_FSYNC;
server.aof_no_fsync_on_rewrite = CONFIG_DEFAULT_AOF_NO_FSYNC_ON_REWRITE;
server.aof_rewrite_perc = AOF_REWRITE_PERC;
server.aof_rewrite_min_size = AOF_REWRITE_MIN_SIZE;
server.aof_rewrite_base_size = 0;
server.aof_rewrite_scheduled = 0;
server.aof_last_fsync = time(NULL);
server.aof_rewrite_time_last = -1;
server.aof_rewrite_time_start = -1;
server.aof_lastbgrewrite_status = C_OK;
server.aof_delayed_fsync = 0;
server.aof_fd = -1;
server.aof_selected_db = -1; /* Make sure the first time will not match */
server.aof_flush_postponed_start = 0;
server.aof_rewrite_incremental_fsync = CONFIG_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC;
server.aof_load_truncated = CONFIG_DEFAULT_AOF_LOAD_TRUNCATED;
server.aof_use_rdb_preamble = CONFIG_DEFAULT_AOF_USE_RDB_PREAMBLE;
server.pidfile = NULL;
server.rdb_filename = zstrdup(CONFIG_DEFAULT_RDB_FILENAME);
server.aof_filename = zstrdup(CONFIG_DEFAULT_AOF_FILENAME);
server.requirepass = NULL;
server.rdb_compression = CONFIG_DEFAULT_RDB_COMPRESSION;
server.rdb_checksum = CONFIG_DEFAULT_RDB_CHECKSUM;
server.stop_writes_on_bgsave_err = CONFIG_DEFAULT_STOP_WRITES_ON_BGSAVE_ERROR;
server.activerehashing = CONFIG_DEFAULT_ACTIVE_REHASHING;
server.active_defrag_running = 0;
server.notify_keyspace_events = 0;
server.maxclients = CONFIG_DEFAULT_MAX_CLIENTS;
server.blocked_clients = 0;
memset(server.blocked_clients_by_type,0,
sizeof(server.blocked_clients_by_type));
server.maxmemory = CONFIG_DEFAULT_MAXMEMORY;
server.maxmemory_policy = CONFIG_DEFAULT_MAXMEMORY_POLICY;
server.maxmemory_samples = CONFIG_DEFAULT_MAXMEMORY_SAMPLES;
server.lfu_log_factor = CONFIG_DEFAULT_LFU_LOG_FACTOR;
server.lfu_decay_time = CONFIG_DEFAULT_LFU_DECAY_TIME;
server.hash_max_ziplist_entries = OBJ_HASH_MAX_ZIPLIST_ENTRIES;
server.hash_max_ziplist_value = OBJ_HASH_MAX_ZIPLIST_VALUE;
server.list_max_ziplist_size = OBJ_LIST_MAX_ZIPLIST_SIZE;
server.list_compress_depth = OBJ_LIST_COMPRESS_DEPTH;
server.set_max_intset_entries = OBJ_SET_MAX_INTSET_ENTRIES;
server.zset_max_ziplist_entries = OBJ_ZSET_MAX_ZIPLIST_ENTRIES;
server.zset_max_ziplist_value = OBJ_ZSET_MAX_ZIPLIST_VALUE;
server.hll_sparse_max_bytes = CONFIG_DEFAULT_HLL_SPARSE_MAX_BYTES;
server.stream_node_max_bytes = OBJ_STREAM_NODE_MAX_BYTES;
server.stream_node_max_entries = OBJ_STREAM_NODE_MAX_ENTRIES;
server.shutdown_asap = 0;
server.cluster_enabled = 0;
server.cluster_node_timeout = CLUSTER_DEFAULT_NODE_TIMEOUT;
server.cluster_migration_barrier = CLUSTER_DEFAULT_MIGRATION_BARRIER;
server.cluster_slave_validity_factor = CLUSTER_DEFAULT_SLAVE_VALIDITY;
server.cluster_require_full_coverage = CLUSTER_DEFAULT_REQUIRE_FULL_COVERAGE;
server.cluster_slave_no_failover = CLUSTER_DEFAULT_SLAVE_NO_FAILOVER;
server.cluster_configfile = zstrdup(CONFIG_DEFAULT_CLUSTER_CONFIG_FILE);
server.cluster_announce_ip = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_IP;
server.cluster_announce_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_PORT;
server.cluster_announce_bus_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_BUS_PORT;
server.migrate_cached_sockets = dictCreate(&migrateCacheDictType,NULL);
server.next_client_id = 1; /* Client IDs, start from 1 .*/
server.loading_process_events_interval_bytes = (1024*1024*2);
server.lazyfree_lazy_eviction = CONFIG_DEFAULT_LAZYFREE_LAZY_EVICTION;
server.lazyfree_lazy_expire = CONFIG_DEFAULT_LAZYFREE_LAZY_EXPIRE;
server.lazyfree_lazy_server_del = CONFIG_DEFAULT_LAZYFREE_LAZY_SERVER_DEL;
server.always_show_logo = CONFIG_DEFAULT_ALWAYS_SHOW_LOGO;
server.lua_time_limit = LUA_SCRIPT_TIME_LIMIT;
unsigned int lruclock = getLRUClock();
atomicSet(server.lruclock,lruclock);
resetServerSaveParams();
appendServerSaveParams(60*60,1); /* save after 1 hour and 1 change */
appendServerSaveParams(300,100); /* save after 5 minutes and 100 changes */
appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
/* Replication related */
server.masterauth = NULL;
server.masterhost = NULL;
server.masterport = 6379;
server.master = NULL;
server.cached_master = NULL;
server.master_initial_offset = -1;
server.repl_state = REPL_STATE_NONE;
server.repl_syncio_timeout = CONFIG_REPL_SYNCIO_TIMEOUT;
server.repl_serve_stale_data = CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA;
server.repl_slave_ro = CONFIG_DEFAULT_SLAVE_READ_ONLY;
server.repl_slave_lazy_flush = CONFIG_DEFAULT_SLAVE_LAZY_FLUSH;
server.repl_down_since = 0; /* Never connected, repl is down since EVER. */
server.repl_disable_tcp_nodelay = CONFIG_DEFAULT_REPL_DISABLE_TCP_NODELAY;
server.repl_diskless_sync = CONFIG_DEFAULT_REPL_DISKLESS_SYNC;
server.repl_diskless_sync_delay = CONFIG_DEFAULT_REPL_DISKLESS_SYNC_DELAY;
server.repl_ping_slave_period = CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD;
server.repl_timeout = CONFIG_DEFAULT_REPL_TIMEOUT;
server.repl_min_slaves_to_write = CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE;
server.repl_min_slaves_max_lag = CONFIG_DEFAULT_MIN_SLAVES_MAX_LAG;
server.slave_priority = CONFIG_DEFAULT_SLAVE_PRIORITY;
server.slave_announce_ip = CONFIG_DEFAULT_SLAVE_ANNOUNCE_IP;
server.slave_announce_port = CONFIG_DEFAULT_SLAVE_ANNOUNCE_PORT;
server.master_repl_offset = 0;
/* Replication partial resync backlog */
server.repl_backlog = NULL;
server.repl_backlog_size = CONFIG_DEFAULT_REPL_BACKLOG_SIZE;
server.repl_backlog_histlen = 0;
server.repl_backlog_idx = 0;
server.repl_backlog_off = 0;
server.repl_backlog_time_limit = CONFIG_DEFAULT_REPL_BACKLOG_TIME_LIMIT;
server.repl_no_slaves_since = time(NULL);
/* Client output buffer limits */
for (j = 0; j < CLIENT_TYPE_OBUF_COUNT; j++)
server.client_obuf_limits[j] = clientBufferLimitsDefaults[j];
/* Double constants initialization */
R_Zero = 0.0;
R_PosInf = 1.0/R_Zero;
R_NegInf = -1.0/R_Zero;
R_Nan = R_Zero/R_Zero;
/* Command table -- we initiialize it here as it is part of the
* initial configuration, since command names may be changed via
* redis.conf using the rename-command directive. */
server.commands = dictCreate(&commandTableDictType,NULL);
server.orig_commands = dictCreate(&commandTableDictType,NULL);
populateCommandTable();
server.delCommand = lookupCommandByCString("del");
server.multiCommand = lookupCommandByCString("multi");
server.lpushCommand = lookupCommandByCString("lpush");
server.lpopCommand = lookupCommandByCString("lpop");
server.rpopCommand = lookupCommandByCString("rpop");
server.zpopminCommand = lookupCommandByCString("zpopmin");
server.zpopmaxCommand = lookupCommandByCString("zpopmax");
server.sremCommand = lookupCommandByCString("srem");
server.execCommand = lookupCommandByCString("exec");
server.expireCommand = lookupCommandByCString("expire");
server.pexpireCommand = lookupCommandByCString("pexpire");
server.xclaimCommand = lookupCommandByCString("xclaim");
/* Slow log */
server.slowlog_log_slower_than = CONFIG_DEFAULT_SLOWLOG_LOG_SLOWER_THAN;
server.slowlog_max_len = CONFIG_DEFAULT_SLOWLOG_MAX_LEN;
/* Latency monitor */
server.latency_monitor_threshold = CONFIG_DEFAULT_LATENCY_MONITOR_THRESHOLD;
/* Debugging */
server.assert_failed = "<no assertion failed>";
server.assert_file = "<no file>";
server.assert_line = 0;
server.bug_report_start = 0;
server.watchdog_period = 0;
}
initServer
void initServer(void) {
int j;
signal(SIGHUP, SIG_IGN);
signal(SIGPIPE, SIG_IGN);
setupSignalHandlers();
if (server.syslog_enabled) {
openlog(server.syslog_ident, LOG_PID | LOG_NDELAY | LOG_NOWAIT,
server.syslog_facility);
}
server.pid = getpid();
server.current_client = NULL;
server.clients = listCreate();
server.clients_to_close = listCreate();
server.slaves = listCreate();
server.monitors = listCreate();
server.clients_pending_write = listCreate();
server.slaveseldb = -1; /* Force to emit the first SELECT command. */
server.unblocked_clients = listCreate();
server.ready_keys = listCreate();
server.clients_waiting_acks = listCreate();
server.get_ack_from_slaves = 0;
server.clients_paused = 0;
server.system_memory_size = zmalloc_get_memory_size();
//创建共享对象
createSharedObjects();
adjustOpenFilesLimit();
server.el = aeCreateEventLoop(server.maxclients+CONFIG_FDSET_INCR);
if (server.el == NULL) {
serverLog(LL_WARNING,
"Failed creating the event loop. Error message: '%s'",
strerror(errno));
exit(1);
}
server.db = zmalloc(sizeof(redisDb)*server.dbnum);
/* Open the TCP listening socket for the user commands. */
if (server.port != 0 &&
listenToPort(server.port,server.ipfd,&server.ipfd_count) == C_ERR)
exit(1);
/* Open the listening Unix domain socket. */
if (server.unixsocket != NULL) {
unlink(server.unixsocket); /* don't care if this fails */
server.sofd = anetUnixServer(server.neterr,server.unixsocket,
server.unixsocketperm, server.tcp_backlog);
if (server.sofd == ANET_ERR) {
serverLog(LL_WARNING, "Opening Unix socket: %s", server.neterr);
exit(1);
}
anetNonBlock(NULL,server.sofd);
}
/* Abort if there are no listening sockets at all. */
if (server.ipfd_count == 0 && server.sofd < 0) {
serverLog(LL_WARNING, "Configured to not listen anywhere, exiting.");
exit(1);
}
//创建database
for (j = 0; j < server.dbnum; j++) {
server.db[j].dict = dictCreate(&dbDictType,NULL);
server.db[j].expires = dictCreate(&keyptrDictType,NULL);
server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
server.db[j].ready_keys = dictCreate(&objectKeyPointerValueDictType,NULL);
server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
server.db[j].id = j;
server.db[j].avg_ttl = 0;
server.db[j].defrag_later = listCreate();
}
evictionPoolAlloc(); /* Initialize the LRU keys pool. */
server.pubsub_channels = dictCreate(&keylistDictType,NULL);
server.pubsub_patterns = listCreate();
listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
server.cronloops = 0;
server.rdb_child_pid = -1;
server.aof_child_pid = -1;
server.rdb_child_type = RDB_CHILD_TYPE_NONE;
server.rdb_bgsave_scheduled = 0;
server.child_info_pipe[0] = -1;
server.child_info_pipe[1] = -1;
server.child_info_data.magic = 0;
aofRewriteBufferReset();
server.aof_buf = sdsempty();
server.lastsave = time(NULL); /* At startup we consider the DB saved. */
server.lastbgsave_try = 0; /* At startup we never tried to BGSAVE. */
server.rdb_save_time_last = -1;
server.rdb_save_time_start = -1;
server.dirty = 0;
resetServerStats();
/* A few stats we don't want to reset: server startup time, and peak mem. */
server.stat_starttime = time(NULL);
server.stat_peak_memory = 0;
server.stat_rdb_cow_bytes = 0;
server.stat_aof_cow_bytes = 0;
server.cron_malloc_stats.zmalloc_used = 0;
server.cron_malloc_stats.process_rss = 0;
server.cron_malloc_stats.allocator_allocated = 0;
server.cron_malloc_stats.allocator_active = 0;
server.cron_malloc_stats.allocator_resident = 0;
server.lastbgsave_status = C_OK;
server.aof_last_write_status = C_OK;
server.aof_last_write_errno = 0;
server.repl_good_slaves_count = 0;
updateCachedTime();
/* Create the timer callback, this is our way to process many background
* operations incrementally, like clients timeout, eviction of unaccessed
* expired keys and so forth. */
if (aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL) == AE_ERR) {
serverPanic("Can't create event loop timers.");
exit(1);
}
/* Create an event handler for accepting new connections in TCP and Unix
* domain sockets. */
for (j = 0; j < server.ipfd_count; j++) {
if (aeCreateFileEvent(server.el, server.ipfd[j], AE_READABLE,
acceptTcpHandler,NULL) == AE_ERR)
{
serverPanic(
"Unrecoverable error creating server.ipfd file event.");
}
}
if (server.sofd > 0 && aeCreateFileEvent(server.el,server.sofd,AE_READABLE,
acceptUnixHandler,NULL) == AE_ERR) serverPanic("Unrecoverable error creating server.sofd file event.");
/* Register a readable event for the pipe used to awake the event loop
* when a blocked client in a module needs attention. */
if (aeCreateFileEvent(server.el, server.module_blocked_pipe[0], AE_READABLE,
moduleBlockedClientPipeReadable,NULL) == AE_ERR) {
serverPanic(
"Error registering the readable event for the module "
"blocked clients subsystem.");
}
/* Open the AOF file if needed. */
if (server.aof_state == AOF_ON) {
//开启aof文件读取
server.aof_fd = open(server.aof_filename,
O_WRONLY|O_APPEND|O_CREAT,0644);
if (server.aof_fd == -1) {
serverLog(LL_WARNING, "Can't open the append-only file: %s",
strerror(errno));
exit(1);
}
}
/* 32 bit instances are limited to 4GB of address space, so if there is
* no explicit limit in the user provided configuration we set a limit
* at 3 GB using maxmemory with 'noeviction' policy'. This avoids
* useless crashes of the Redis instance for out of memory. */
if (server.arch_bits == 32 && server.maxmemory == 0) {
serverLog(LL_WARNING,"Warning: 32 bit instance detected but no memory limit set. Setting 3 GB maxmemory limit with 'noeviction' policy now.");
server.maxmemory = 3072LL*(1024*1024); /* 3 GB */
server.maxmemory_policy = MAXMEMORY_NO_EVICTION;
}
if (server.cluster_enabled) clusterInit();
replicationScriptCacheInit();
scriptingInit(1);
slowlogInit();
latencyMonitorInit();
bioInit();
server.initial_memory_usage = zmalloc_used_memory();
}