The dgraph increment
tool increments a counter value transactionally. The
increment tool can be used as a health check that an Alpha is able to service
transactions for both queries and mutations.
Example Usage
Increment the default predicate (counter.val
) once. If the predicate doesn’t yet
exist, then it will be created starting at counter 0.
$ dgraph increment
Increment the counter predicate against the Alpha running at address --alpha
(default: localhost:9080
):
$ dgraph increment --alpha=192.168.1.10:9080
Increment the counter predicate specified by --pred
(default: counter.val
):
$ dgraph increment --pred=counter.val.healthcheck
Run a read-only query for the counter predicate and does not run a mutation to increment it:
$ dgraph increment --ro
Run a best-effort query for the counter predicate and does not run a mutation to increment it:
$ dgraph increment --be
Run the increment tool 1000 times every 1 second:
$ dgraph increment --num=1000 --wait=1s
Run increment a few times
$ dgraph increment
0410 10:31:16.379 Counter VAL: 1 [ Ts: 1 ]
$ dgraph increment
0410 10:34:53.017 Counter VAL: 2 [ Ts: 3 ]
$ dgraph increment
0410 10:34:53.648 Counter VAL: 3 [ Ts: 5 ]
Run read-only queries to read the counter a few times
$ dgraph increment --ro
0410 10:34:57.35 Counter VAL: 3 [ Ts: 7 ]
$ dgraph increment --ro
0410 10:34:57.886 Counter VAL: 3 [ Ts: 7 ]
$ dgraph increment --ro
0410 10:34:58.129 Counter VAL: 3 [ Ts: 7 ]
Run best-effort query to read the counter a few times
$ dgraph increment --be
0410 10:34:59.867 Counter VAL: 3 [ Ts: 7 ]
$ dgraph increment --be
0410 10:35:01.322 Counter VAL: 3 [ Ts: 7 ]
$ dgraph increment --be
0410 10:35:02.674 Counter VAL: 3 [ Ts: 7 ]
Run a read-only query to read the counter 5 times
$ dgraph increment --ro --num=5
0410 10:35:18.812 Counter VAL: 3 [ Ts: 7 ]
0410 10:35:18.813 Counter VAL: 3 [ Ts: 7 ]
0410 10:35:18.815 Counter VAL: 3 [ Ts: 7 ]
0410 10:35:18.817 Counter VAL: 3 [ Ts: 7 ]
0410 10:35:18.818 Counter VAL: 3 [ Ts: 7 ]
Increment the counter 5 times
$ dgraph increment --num=5
0410 10:35:24.028 Counter VAL: 4 [ Ts: 8 ]
0410 10:35:24.061 Counter VAL: 5 [ Ts: 10 ]
0410 10:35:24.104 Counter VAL: 6 [ Ts: 12 ]
0410 10:35:24.145 Counter VAL: 7 [ Ts: 14 ]
0410 10:35:24.178 Counter VAL: 8 [ Ts: 16 ]
Increment the counter 5 times, once every second.
$ dgraph increment --num=5 --wait=1s
0410 10:35:26.95 Counter VAL: 9 [ Ts: 18 ]
0410 10:35:27.975 Counter VAL: 10 [ Ts: 20 ]
0410 10:35:28.999 Counter VAL: 11 [ Ts: 22 ]
0410 10:35:30.028 Counter VAL: 12 [ Ts: 24 ]
0410 10:35:31.054 Counter VAL: 13 [ Ts: 26 ]
If the Alpha is too busy or unhealthy, the tool will timeout and retry.
$ dgraph increment
0410 10:36:50.857 While trying to process counter: Query error: rpc error: code = DeadlineExceeded desc = context deadline exceeded. Retrying...
This is a companion discussion topic for the original entry at https://dgraph.io/docs/howto/using-increment-tool/