Shulou(Shulou.com)06/01 Report--

redis Profile Parameter Descriptions:

1. Redis does not run as a daemon by default. It can be modified through this configuration item. Use yes to enable daemons.

daemonize no

2. When Redis runs as a daemon, Redis writes pid to the file/var/run/redis.pid by default, which can be specified via pidfile.

pidfile /var/run/redis.pid

3. Specify Redis listening port, default port is 6379, the author explained in his own blog post why 6379 as the default port, because 6379 on the phone button corresponding to the number MERZ, and MERZ from the Italian singer Alessia Merz name

port 6379

4. bound host address

bind 127.0.0.1

5. How long does the client idle before closing the connection? If specified as 0, it means closing the function.

timeout 300

6. Specify the logging level. Redis supports four levels: debug, verbose, notice, warning. The default is verbose.

loglevel verbose

7. Logging mode, default is standard output, if Redis is configured to run as a daemon, and here is configured to log as standard output, then the log will be sent to/dev/null

logfile stdout

8. Set the number of databases, default database is 0, you can use SELECT command to specify database id on the connection

databases 16

9. Specifies how many updates occur over a period of time to synchronize data to a data file, which can be matched by multiple conditions

save

The Redis default configuration file provides three conditions:

save 900 1

save 300 10

save 60 10000

1 change in 900 seconds (15 minutes), 10 changes in 300 seconds (5 minutes), and 10000 changes in 60 seconds.

10. Specify whether to compress data when storing to local database, default is yes, Redis uses LZF compression, if to save CPU time, you can turn off this option, but it will cause database files to become huge

rdbcompression yes

11. Specifies the local database file name, the default is dump.rdb

dbfilename dump.rdb

12. Specify the directory where the local database resides

dir ./

13. Set the IP address and port of the master service when this machine is slav service. When Redis starts, it will automatically synchronize data from the master.

slaveof

14. When the master service is password protected, the slav service connects to the master password

masterauth

15. Set the Redis connection password. If the connection password is configured, the client needs to provide the password through the AUTH command when connecting to Redis. It is closed by default.

requirepass foobared

16. Set the maximum number of client connections at the same time. By default, there is no limit. The number of client connections that Redis can open at the same time is the maximum number of file descriptors that Redis can open. If maxclients 0 is set, it means there is no limit. When the client connection limit is reached, Redis closes the new connection and returns the max number of clients reached error message to the client.

maxclients 128

17. Specify the maximum memory limit of Redis. Redis loads data into memory at startup. After reaching the maximum memory, Redis will first try to clear expired or expiring keys. When this method is processed, it still reaches the maximum memory setting. Write operations cannot be performed, but read operations can still be performed. Redis 'new vm mechanism will store Key in memory and Value in swap area

maxmemory

18. Specifies whether to log after each update operation. Redis writes data to disk asynchronously by default, and if not turned on, may cause data loss for a period of time during a power outage. Because redis itself synchronizes data files according to the above save condition, some data will only exist in memory for a period of time. default is no

appendonly no

19. Specifies the update log file name, default is appendonly.aof

appendfilename appendonly.aof

20. Specifies the update log criteria, with 3 optional values:

no: indicates that the operating system synchronizes the data cache to disk (fast)

always: means manually calling fsync() after each update operation to write data to disk (slow, safe)

everysec: indicates synchronization once per second (compromise, default)

appendfsync everysec

21. Specify whether to enable the virtual memory mechanism, the default value is no, a brief introduction, VM mechanism will page data storage, by Redis will access less pages, that is, cold data swap to disk, access more pages from disk automatically swapped out to memory (in the following articles I will carefully analyze Redis VM mechanism)

vm-enabled no

22. Virtual memory file path, default value is/tmp/redis.swap, multiple Redis instances cannot be shared

vm-swap-file /tmp/redis.swap

23. Store all data greater than vm-max-memory in virtual memory. No matter how small vm-max-memory is set, all index data is stored in memory (Redis index data is keys). That is, when vm-max-memory is set to 0, all values exist on disk. Default is 0

vm-max-memory 0

24. Redis swap file is divided into many pages, an object can be saved on multiple pages, but a page cannot be shared by multiple objects, vm-page-size is to be set according to the size of the stored data, the author suggests that if you store a lot of small objects, the page size is best set to 32 or 64bytes; if you store a lot of large objects, you can use a larger page, if you are not sure, use the default value

vm-page-size 32

25. Set the number of pages in a swap file. Since page tables (a bitmap indicating free or used pages) are stored in memory, every eight pages on disk consumes 1 byte of memory.

vm-pages 134217728

26. Set the number of threads accessing the swap file, preferably not more than the number of cores on the machine. If set to 0, all operations on the swap file are serial, which may cause a long delay. default value is 4

vm-max-threads 4

27. Set whether to merge smaller packets into one packet when replying to the client. Default is ON

glueoutputbuf yes

28. Specifies that a special hash algorithm is used when more than a certain number or the largest element exceeds a certain threshold

hash-max-zipmap-entries 64

hash-max-zipmap-value 512

29. Specifies whether to activate reset hash, default is on (described later in detail when introducing Redis hash algorithm)

activerehashing yes

30. Specify to include other profiles. You can use the same profile across multiple Redis instances on the same host, while each instance has its own specific profile.

include /path/to/local.conf

31. Log to syslog

syslog-enabled no

32. After configuring the save parameter, after a save point, there may be disk corruption or permission problems. If the following parameter is set to yes, redis will still work normally.

Whether to continue working when persistence errors occur, and whether to terminate all client write requests. The default setting of "yes" indicates termination. Once snapshot data storage fails, this server is a read-only service.

If "no," then this snapshot fails, but the next snapshot is unaffected, but if a failure occurs, the data can only recover to the "last success point"

stop-writes-on-bgsave-error yes

33. When the slave is disconnected from the master link, if this value is yes, when the client queries the slave, it will respond to the client. If it is the first synchronization, it will return a date data or this null value. If it is set to no, it will return "SYNC with master in progress" to INFO and SLAVEFO.

slave-serve-stale-data yes

34. Read only from server (default)

slave-read-only yes

35. Time interval from ping to master (in seconds)

repl-ping-slave-period 10

36. Bulk transfer I / O timeout and main data or ping response timeout default 60s must be greater than repl-ping-slave-period value

repl-timeout 60

37. If this option is "yes" then Redis uses fewer TCP packets and less bandwidth to send data to, which occurs with a delay of 40 ms (40 ms in the Linux kernel) from the host.

If no will reduce latency in slave, but traffic usage will be relatively high. If multiple slave hosts are used, it is recommended to set yes here.

repl-disable-tcp-nodelay no

38. The priority of the slave host. If the master host hangs up, one of the slave hosts will be selected as the master of other slaves. The lowest priority number will become the master first. 0 is a special level. 0 will never become the master. The default value is 100.

slave-priority 100

39. "Slow operation log" record, unit: microseconds (millionth of a second, 1000 * 1000), if the operation time exceeds this value, the command message will be "recorded". (memory, not files).

The "operation time" does not include network IO expenses, but only the time for "memory implementation" after the request reaches the server. "0" means record all operations

slowlog-log-slower-than 10000

40. The maximum number of records to keep in the Slow Log will be queued, and if this length is exceeded, old records will be removed.

SLOWLOG args can be viewed (SLOWLOG get 10,SLOWLOG reset)

slowlog-max-len 1000

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