BBlack has submitted this change and it was merged. Change subject: r::c::perf: disable autocorking ......................................................................
r::c::perf: disable autocorking Change-Id: I96a2504dc1a6e53c1eed880a7a50dd94591581e7 --- M modules/role/manifests/cache/perf.pp 1 file changed, 13 insertions(+), 0 deletions(-) Approvals: BBlack: Looks good to me, approved jenkins-bot: Verified diff --git a/modules/role/manifests/cache/perf.pp b/modules/role/manifests/cache/perf.pp index 4d6e622..d039d8e 100644 --- a/modules/role/manifests/cache/perf.pp +++ b/modules/role/manifests/cache/perf.pp @@ -147,6 +147,19 @@ 'net.ipv4.tcp_synack_retries' => 2, 'net.ipv4.tcp_syn_retries' => 2, + # TCP autocorking exists and defaults on from 3.14 onwards. The + # idea is that some applications that should be doing a better job + # of local buffering or manual TCP_CORK aren't, and the kernel + # detects the common patterns for this and auto-corks for them + # (doesn't immediately send a small write, instead waits a bit to + # see if it can coalesce it with another). Netstat counters for + # autocorking are running up at a huge rate (ballpark near our reqs + # or SYNs rate), which implies this is happening commonly to nginx + # outbound traffic. My theory is this is probably a net loss and + # nginx and/or openssl know what they're doing and we'd benefit from + # the writes going out immediately and not autocorking... + 'net.ipv4.tcp_autocorking' => 0, + # Pure perf hacks (documented above) 'net.ipv4.tcp_notsent_lowat' => 131072, 'net.ipv4.tcp_slow_start_after_idle' => 0, -- To view, visit https://gerrit.wikimedia.org/r/295588 To unsubscribe, visit https://gerrit.wikimedia.org/r/settings Gerrit-MessageType: merged Gerrit-Change-Id: I96a2504dc1a6e53c1eed880a7a50dd94591581e7 Gerrit-PatchSet: 1 Gerrit-Project: operations/puppet Gerrit-Branch: production Gerrit-Owner: BBlack <bbl...@wikimedia.org> Gerrit-Reviewer: BBlack <bbl...@wikimedia.org> Gerrit-Reviewer: jenkins-bot <> _______________________________________________ MediaWiki-commits mailing list MediaWiki-commits@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/mediawiki-commits