On Tue, 2017-08-22 at 11:12 +0530, Akshat Kakkar wrote: > There are multiple hosts/clients. All are mainly windows based. > > Timestamp is not used as my clients mainly are windows based and in > that it tcp timestamp is by defauly disabled. > > sysctl is as follows: > > kernel.shmmax = 68719476736 > kernel.shmall = 4294967296 > kernel.pid_max=4194303 > vm.max_map_count=131072 > kernel.sem=250 32000 32 250 > > net.netfilter.nf_conntrack_generic_timeout = 300 > net.netfilter.nf_conntrack_tcp_timeout_syn_sent = 60 > net.netfilter.nf_conntrack_tcp_timeout_syn_recv = 30 > net.netfilter.nf_conntrack_tcp_timeout_established = 7200 > net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 60 > net.netfilter.nf_conntrack_tcp_timeout_close_wait = 30 > net.netfilter.nf_conntrack_tcp_timeout_last_ack = 30 > net.netfilter.nf_conntrack_tcp_timeout_time_wait = 60 > net.netfilter.nf_conntrack_tcp_timeout_close = 10 > net.netfilter.nf_conntrack_tcp_timeout_max_retrans = 300 > net.netfilter.nf_conntrack_tcp_timeout_unacknowledged = 300 > net.netfilter.nf_conntrack_udp_timeout = 30 > net.netfilter.nf_conntrack_udp_timeout_stream = 180 > net.netfilter.nf_conntrack_icmp_timeout = 30 > net.netfilter.nf_conntrack_events_retry_timeout = 15 > net.core.rmem_max = 8388608 > net.core.wmem_max = 8388608 > > net.ipv4.tcp_tw_reuse=1 > net.ipv4.tcp_tw_recycle=1
This is exactly what I feared. We do not support tcp_tw_reuse = 1 AND tcp_tw_recycle = 1 This is a very well known bad combination. > net.ipv4.tcp_fin_timeout=30 > net.ipv4.tcp_keepalive_time=1800 > net.ipv4.tcp_keepalive_intvl=60 > net.ipv4.tcp_keepalive_probes=20 > net.ipv4.tcp_max_syn_backlog=4096 > net.ipv4.tcp_syncookies=1 > net.ipv4.tcp_sack=1 > net.ipv4.tcp_dsack=1 > net.ipv4.tcp_window_scaling=1 > net.ipv4.tcp_syn_retries=3 > net.ipv4.tcp_synack_retries=3 > net.ipv4.tcp_retries1=3 > net.ipv4.tcp_retries2=15 > net.ipv4.ip_local_port_range=1024 65535 > > net.ipv4.tcp_timestamps=0 > > net.core.netdev_max_backlog=10000 This is an insane backlog. > net.core.somaxconn=100000 > net.core.optmem_max=81920 > > net.netfilter.nf_conntrack_max=524288 > net.nf_conntrack_max=524288 > net.ipv6.conf.all.disable_ipv6 = 1 > fs.file-max=1000000 > > net.ipv4.tcp_no_metrics_save = 1 > net.ipv4.tcp_max_syn_backlog = 10240 > net.ipv4.tcp_congestion_control=htcp > > net.ipv4.tcp_rfc1337 = 1 > net.core.netdev_max_backlog = 65536 This is a crazy backlog. Do not do that. > net.ipv4.tcp_max_tw_buckets = 1440000 > > net.core.rmem_max = 134217728 > net.core.wmem_max = 134217728 > > > It looks like your sysctls have been set to unreasonable values.
