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:

command line tool to monitor that database is available for read & write

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

Options:
  -d, --dsn <dsn>            <mysql|postgres>://<username>:<password>@tcp(<host>:<port>)/<database> [env: DBPULSE_DSN=postgres://postgres:secret@tcp(localhost)/dbpulse]
  -i, --interval <interval>  number of seconds between checks [env: DBPULSE_INTERVAL=] [default: 30]
  -p, --port <port>          listening port for /metrics [env: DBPULSE_PORT=] [default: 9300]
  -r, --range <range>        The upper limit of the ID range [env: DBPULSE_RANGE=] [default: 100]
  -h, --help                 Print help
  -V, --version              Print version

Example:

dbpulse --dsn "postgres://postgres:secret@tcp(10.10.0.10)/dbpulse" -r 2880

the app tries to create the database if it does not exist (depends on the user permissions)

rpm

To create an RPM package:

just rpm

you need to have just installed and docker running

Then you need to copy the dbpulse*.x86_64.rpm:

cp target/generate-rpm/dbpulse-*-x86_64.rpm /host