backend_toolate count suddenly drops after upgrade from 2.1.3 too 2.1.5

[Johnny Halfmoon]

Hiya,

today I upgraded a few Varnish servers from v2.1.3 to v2.1.5. The machines are purring along nicely, but I did notice something curious on in the server's statistics: the backend_toolate is down from a very wobbly average of 20p/s too a constant 0.7p/s. Also , the object & object head count are way down. n_lru_nuked is also down from an average of 10p/s to zero. Hitrate is unaffected and performance is slightly up (a few percent less cpuload on high-traffic moments).

This is no temporary effect, because I've seen it on another machine in the same cluster, which I upgraded a week ago. I did a quick comparison between 2.1.3 and 2.1.5 of varnishadm's 'param.show' and also a quick scan of the sourcecode of 2.1.3 & 2.1.5, but couldn't find any parameter defaults that might have been changed between versions.

It's not causing any issues here, other that a bit more performance. I'm just curious: Does anybody know what's going on here?

Cheers,

Johhny

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