Sentinel (error) ERR No such master with that name

[ch...@netki.com]

Redis server v=3.2.0 sha=00000000:0 malloc=jemalloc-4.0.3 bits=64 build=c0a5df8b4ee6e49

Hello,

I am running 1Master/1Slave Redis on port 6379 with 4 sentinels and a quorum of 3. My goal is to experiment with some timeout values in the sentinel.conf file.

I'm finding that I can't seem to change any of these values in sentinel.conf (redis refuses to start); and when I try to make changes during runtime, it shows errors that there is "no such master by that name" but I'm not sure I understand what mis-configuration I did that could be causing this? 

I've rummaged around online and haven't had much luck with this.

Any pointers would be very appreciated!

Example:

127.0.0.1:26379> SENTINEL SET failover-timeout mymaster 180000

(error) ERR No such master with that name

Yet (from the same sentinel instance) this command appears to have some notion of the 'mymaster' name:

127.0.0.1:26379> sentinel master mymaster

 1) "name"

 2) "mymaster"

 3) "ip"

 4) "10.0.20.83"

 5) "port"

 6) "6379"

 7) "runid"

 8) "db6774e7680a607131c9a520e31a4980f7d7b37a"

 9) "flags"

10) "master"

11) "link-pending-commands"

12) "0"

13) "link-refcount"

14) "1"

15) "last-ping-sent"

16) "0"

17) "last-ok-ping-reply"

18) "264"

19) "last-ping-reply"

20) "264"

21) "down-after-milliseconds"

22) "30000"

23) "info-refresh"

24) "7496"

25) "role-reported"

26) "master"

27) "role-reported-time"

28) "1031548"

29) "config-epoch"

30) "13"

31) "num-slaves"

32) "1"

33) "num-other-sentinels"

34) "3"

35) "quorum"

36) "3"

37) "failover-timeout"

38) "180000"

39) "parallel-syncs"

40) "1"

Logs show:

4198:X 20 Jul 19:10:01.215 # Sentinel ID is 8ad52c70b49a092b0e9187ab103c5463901dc07b

4198:X 20 Jul 19:10:01.215 # +monitor master mymaster 10.0.20.83 6379 quorum 3

[The Real Bill]

You have the order of arguments wrong. The API isn't tr same as the config file.
Use:
Sentinel set mymaster directive value

[ch...@netki.com]

Thanks so much The Real Bill -- I was definitely getting tunnel-visioned there.