In this blog post, I investigate a case of spiking InnoDB Rows
inserted in the absence of a write query, and find internal
temporary tables to be the culprit.
Recently I was investigating an interesting case for a customer.
We could see the regular spikes on a graph depicting “InnoDB rows
inserted” metric (jumping from 1K/sec to 6K/sec), however we were
not able to correlate those spikes with other activity. The
innodb_row_inserted
graph (picture from PMM demo) looked similar to this (but on a
much larger scale):
Other graphs (Com_*, Handler_*) did not show any spikes like
that. I’ve examined the logs (we were not able to enable general
log or change the threshold of the slow log), performance_schema,
triggers, stored procedures, prepared statements and even
reviewed the binary logs. However, I was not able to find any
single …
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