dbpulse

dbpulse will run a set of queries in a defined interval, in order to dynamically test if the database is available mainly for writes, it exposes a /metrics endpoint the one can be used together with Prometheus and create alerts when the database is not available, this is to cover HALT/LOCK cases in Galera clusters in where a DDL could stale the whole cluster or flow-control kicks in and the database could not be receiving COMMITS/WRITE.

How to use it

Run it as a client, probably hitting your load balancer so that you can test like if you where a client, you need to pass the DSN or see it up as an environment var.

/metrics

The dbpulse_pulse is a gauge will return 1 when DB is healthy (read/write) OK,

The calculate the runtime:

sum(rate(dbpulse_runtime_sum[5m])) / sum(rate(dbpulse_runtime_count[5m]))

Current options:

USAGE:
    dbpulse [OPTIONS] --dsn <dsn>

OPTIONS:
        --46                     listen in both IPv4 and IPv6
        --dsn <dsn>              mysql://<username>:<password>@tcp(<host>:<port>)/<database> [env: DSN=]
    -h, --help                   Print help information
    -i, --interval <interval>    number of seconds between checks [env: INTERVAL=] [default: 30]
    -p, --port <port>            listening port for /metrics [env: PORT=] [default: 9300]
    -V, --version                Print version information