Include 'refresh' and 'flush' stats by default when using 'node-stats-include-indices'

[b-deam]

Title. These stats are super useful and we should include them by default.

[dliappis]

Title. These stats are super useful and we should include them by default.

Any thoughts about the performance impact? We used to have issues in the past, see the warning here and while they don't look like big structures, I am always concerned about what happens under the hood in ES when asking for extra things in node-stats.

[b-deam]

Title. These stats are super useful and we should include them by default.

Any thoughts about the performance impact? We used to have issues in the past, see the warning here and while they don't look like big structures, I am always concerned about what happens under the hood in ES when asking for extra things in node-stats.

We already retrieve the full node stats output (no pre-filtering):

rally/esrally/telemetry.py

Line 942 in c90169e

stats = self.client.nodes.stats(metric="_all")

So the only extra overhead is parsing for these objects in the node stats response, and the additional 9 keys in the respective sample's dict.

[dliappis]

LGTM