Collect host_cache metrics, .e.g COUNT_HOST_BLOCKED_ERRORS

[estahn]

Problem

We have seen various issues in our logs looking like this:

Error: ER_HOST_IS_BLOCKED: Host '10.10.5.115' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'

We would like to have metrics and possibly alert on this.

The following query returns information about the hosts:

SELECT * FROM performance_schema.host_cache WHERE IP = '10.10.5.115'

We're primarily interested in COUNT_HOST_BLOCKED_ERRORS.

[SuperQ]

Seems like some useful data, exposing per-IP would probably be too much cardinality,

We would likely want to sum up the errors like this:

SELECT
  sum(COUNT_HOST_BLOCKED_ERRORS) AS blocked_errors_total
  FROM performance_schema.host_cache

[estahn]

Yes, I was thinking the same after posting the feature request. Aggregating this should be good enough.

On Thu, 1 Apr 2021 at 7:45 pm, Ben Kochie @.***> wrote:

Seems like some useful data, exposing per-IP would probably be too much cardinality,

We would likely want to sum up the errors like this:

SELECT sum(COUNT_HOST_BLOCKED_ERRORS) AS blocked_errors_total FROM performance_schema.host_cache

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