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author | Julian Anastasov <ja@ssi.bg> | 2020-07-01 18:17:19 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-19 09:14:56 +0300 |
commit | 7106f943302247ed9fcde84afdca06cbe9e19dce (patch) | |
tree | 24bf38015522f504774ffc421ef70b584cbcb8bd /include | |
parent | fdac85326f40c7ba6ae2b9e4a2c710f26b708ab8 (diff) | |
download | linux-7106f943302247ed9fcde84afdca06cbe9e19dce.tar.xz |
ipvs: allow connection reuse for unconfirmed conntrack
[ Upstream commit f0a5e4d7a594e0fe237d3dfafb069bb82f80f42f ]
YangYuxi is reporting that connection reuse
is causing one-second delay when SYN hits
existing connection in TIME_WAIT state.
Such delay was added to give time to expire
both the IPVS connection and the corresponding
conntrack. This was considered a rare case
at that time but it is causing problem for
some environments such as Kubernetes.
As nf_conntrack_tcp_packet() can decide to
release the conntrack in TIME_WAIT state and
to replace it with a fresh NEW conntrack, we
can use this to allow rescheduling just by
tuning our check: if the conntrack is
confirmed we can not schedule it to different
real server and the one-second delay still
applies but if new conntrack was created,
we are free to select new real server without
any delays.
YangYuxi lists some of the problem reports:
- One second connection delay in masquerading mode:
https://marc.info/?t=151683118100004&r=1&w=2
- IPVS low throughput #70747
https://github.com/kubernetes/kubernetes/issues/70747
- Apache Bench can fill up ipvs service proxy in seconds #544
https://github.com/cloudnativelabs/kube-router/issues/544
- Additional 1s latency in `host -> service IP -> pod`
https://github.com/kubernetes/kubernetes/issues/90854
Fixes: f719e3754ee2 ("ipvs: drop first packet to redirect conntrack")
Co-developed-by: YangYuxi <yx.atom1@gmail.com>
Signed-off-by: YangYuxi <yx.atom1@gmail.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/net/ip_vs.h | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index af0ede9ad4d0..c31e54a41b5c 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -1614,18 +1614,16 @@ static inline void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp) } #endif /* CONFIG_IP_VS_NFCT */ -/* Really using conntrack? */ -static inline bool ip_vs_conn_uses_conntrack(struct ip_vs_conn *cp, - struct sk_buff *skb) +/* Using old conntrack that can not be redirected to another real server? */ +static inline bool ip_vs_conn_uses_old_conntrack(struct ip_vs_conn *cp, + struct sk_buff *skb) { #ifdef CONFIG_IP_VS_NFCT enum ip_conntrack_info ctinfo; struct nf_conn *ct; - if (!(cp->flags & IP_VS_CONN_F_NFCT)) - return false; ct = nf_ct_get(skb, &ctinfo); - if (ct) + if (ct && nf_ct_is_confirmed(ct)) return true; #endif return false; |