redis使用記憶體調整及最佳化

redis使用記憶體調整及最佳化
redis使用記憶體調整及最佳化1、查看當前記憶體使用量情況

[root@redis01 ~]# redis-cli info# Serverredis_version:2.8.19redis_git_sha1:00000000redis_git_dirty:0redis_build_id:c0359e7aa3798aa2redis_mode:standaloneos:Linux 3.10.0-123.el7.x86_64 x86_64arch_bits:64multiplexing_api:epollgcc_version:4.8.3process_id:24191run_id:36ad15148d3478f13076b6feb065536c7dca4adctcp_port:6379uptime_in_seconds:173800uptime_in_days:2hz:10lru_clock:14099001config_file:/etc/redis.conf# Clientsconnected_clients:84client_longest_output_list:0client_biggest_input_buf:0blocked_clients:0# Memoryused_memory:14187404192used_memory_human:13.21Gused_memory_rss:14567976960used_memory_peak:14189556584used_memory_peak_human:13.22Gused_memory_lua:35840mem_fragmentation_ratio:1.03mem_allocator:jemalloc-3.6.0# Persistenceloading:0rdb_changes_since_last_save:130135rdb_bgsave_in_progress:1rdb_last_save_time:1490493874rdb_last_bgsave_status:okrdb_last_bgsave_time_sec:100rdb_current_bgsave_time_sec:74aof_enabled:0aof_rewrite_in_progress:0aof_rewrite_scheduled:0aof_last_rewrite_time_sec:-1aof_current_rewrite_time_sec:-1aof_last_bgrewrite_status:okaof_last_write_status:ok# Statstotal_connections_received:280094total_commands_processed:228769139instantaneous_ops_per_sec:1111total_net_input_bytes:14293923616total_net_output_bytes:42883168734instantaneous_input_kbps:72.58instantaneous_output_kbps:77.55rejected_connections:0sync_full:1sync_partial_ok:0sync_partial_err:1expired_keys:38545evicted_keys:0keyspace_hits:33635872keyspace_misses:302049pubsub_channels:0pubsub_patterns:4latest_fork_usec:195303# Replicationrole:masterconnected_slaves:1slave0:ip=x.0.x.x,port=6379,state=online,offset=11332087470,lag=0master_repl_offset:11332106737  ##  已修改隱藏實際iprepl_backlog_active:1repl_backlog_size:1048576repl_backlog_first_byte_offset:11331058162repl_backlog_histlen:1048576# CPUused_cpu_sys:6134.57used_cpu_user:2565.36used_cpu_sys_children:8045.19used_cpu_user_children:97035.76# Keyspacedb0:keys=337475,expires=180183,avg_ttl=1286629728

2、分析實際記憶體消耗已經13G

used_memory_human:13.21G

查看zabbix內redis使用記憶體的最近一個月記錄

一個月前3.5G，線性增長到到13G

平均到期時間

db0:keys=337475,expires=180183,avg_ttl=1286629728

實際記憶體設定

[root@redis01 ~]# redis-cli config get maxmemory1) "maxmemory"2) "0"

3、最佳化措施3.1、設定記憶體限制，防止達到記憶體最大限制宕機設定記憶體最大使用量為10G，先調整運行時

127.0.0.1:6379> config set maxmemory 10737418240OK(10.76s)127.0.0.1:6379> info......# Memoryused_memory:10730048552used_memory_human:9.99G

設定redis.conf，下次重啟生效

maxmemory 10737418240

3.2、調整到期時間，清理到期時間keys佔用記憶體

預設到期時間移交開發調整，avg_ttl單位為ms，換成後平均為15天，相當長的時間；未設定預設到期時間的keys，移交開發調整；

3.3、調整系統參數，保證bgsave正常運行

[root@redis01 ~]# cat /etc/sysctl.confvm.overcommit_memory = 1

運行命令後生效

sysctl -p 

3.4、分析keys，找出使用記憶體最大的keys列表交開發分析安裝redis-rdb-tools

過程略

產生redis快照

rdb -c memory dump.rdb > memory.csv   #dump.rdb為redis產生的dump檔案

尋找記憶體用量最大的20個對象

sort -t, -k4nr memory.csv |heand -n 20