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This article mainly explains the "Redis4.0 copy error from the library" master_link_status:down "how to deal with", the article explains the content is simple and clear, easy to learn and understand, the following please follow the editor's ideas slowly in depth, together to study and learn "Redis4.0 copy error from the library" master_link_status:down "how to deal with it"!

Environment description:

Redis version: 4.0.2

Main library: 192.168.0.190

Slave library: 192.168.0.191

Today, the Zabbix alarm has been showing redis sync error messages, so log in to redis to find that the replication status from the library has always been master_link_status:down status.

The error message from the library log is as follows:

17365V 28 Dec 14 Dec 45R 15.294 * Connecting to MASTER 192.168.0.190V 6379

17365V 28 Dec 14 Dec 45R 15.294 * MASTER SLAVE sync started

17365V 28 Dec 1415 Dec 15.294 *.

17365 replication can continue... S 28 Dec 1415 Dec 15.295 * Master replied to PING

17365 no cached master S 28 Dec 1415 15 * Partial resynchronization not possible (no cached master)

17365V 28 Dec 14 Dec 4515 * 341 * Full resync from master: 3987160bba8279fe30b828fb339d1c0c6536a3ab:182474982617073

17365:S 28 Dec 14:45:17.293 # I/O error reading bulk count from MASTER: Resource temporarily unavailable

The error log information of the main database is as follows:

25573 Background saving started by pid M 28 Dec 1514 38 * Background saving started by pid 12067

25573:M 28 Dec 15:38:53.258 # Client id=87019085 addr=192.168.0.191:1440 fd=110 name= age=0 idle=0 flags=S db=0 sub=0 psub=0 multi=-1 qbuf=0 qbuf-free=0 obl=6641 oll=1 omem=19125 events=r cmd=psync scheduled to be closed ASAP for overcoming of output buffer limits.

25573:M 28 Dec 15:38:53.356 # Connection with slave 192.168.0.191:6379 lost.

From the master database log, we can see that when the redis master library receives a request from the slave library to resynchronize the data, it becomes a rdb file, and then uses psync to do partial synchronization. We can see that the problem lies in this part.

The error "psync scheduled to be closed ASAP" continues to be reported because the client-output-buffer-limit value is set too low, which causes the data to fail.

Solution:

Log in to the master library and modify the buffer size limit of the slave library:

127.0.1 6379 > config set client-output-buffer-limit "slave 8589934592 2147483648 0"

OK

Synchronize to profile:

127.0.0.1 purl 6379 > config rewrite

OK

View the contents of the profile

# cat redis.conf | grep client-output-buffer-limit

Client-output-buffer-limit normal 0 0 0

Client-output-buffer-limit slave 8gb 2gb 0

Log in to the slave library 192.168.0.191, observe the master-slave replication status again, and find that the replication status of the slave library will soon become up:

# redis-cli info replication

# Replication

Role:slave

Master_host:192.168.0.190

Master_port:6379

Master_link_status:up

So far, the problem has been dealt with.

Thank you for your reading, the above is "Redis4.0 copy error from the library" master_link_status:down "how to deal with" the content, after the study of this article, I believe that you copy Redis4.0 from the library error report "master_link_status:down" how to deal with this problem has a deeper understanding, the specific use of the situation also needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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