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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
commit | be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97 (patch) | |
tree | 9754ff1ca740f6346cf8483ec915d4054bc5da2d /health/health.d/tcp_listen.conf | |
parent | Initial commit. (diff) | |
download | netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.tar.xz netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.zip |
Adding upstream version 1.44.3.upstream/1.44.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | health/health.d/tcp_listen.conf | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/health/health.d/tcp_listen.conf b/health/health.d/tcp_listen.conf new file mode 100644 index 00000000..9d1104a5 --- /dev/null +++ b/health/health.d/tcp_listen.conf @@ -0,0 +1,100 @@ +# +# There are two queues involved when incoming TCP connections are handled +# (both at the kernel): +# +# SYN queue +# The SYN queue tracks TCP handshakes until connections are fully established. +# It overflows when too many incoming TCP connection requests hang in the +# half-open state and the server is not configured to fall back to SYN cookies. +# Overflows are usually caused by SYN flood DoS attacks (i.e. someone sends +# lots of SYN packets and never completes the handshakes). +# +# Accept queue +# The accept queue holds fully established TCP connections waiting to be handled +# by the listening application. It overflows when the server application fails +# to accept new connections at the rate they are coming in. +# +# +# ----------------------------------------------------------------------------- +# tcp accept queue (at the kernel) + + alarm: 1m_tcp_accept_queue_overflows + on: ip.tcp_accept_queue + class: Workload + type: System +component: Network + os: linux + hosts: * + lookup: average -60s unaligned absolute of ListenOverflows + units: overflows + every: 10s + warn: $this > 1 + crit: $this > (($status == $CRITICAL) ? (1) : (5)) + delay: up 0 down 5m multiplier 1.5 max 1h + summary: System TCP accept queue overflows + info: Average number of overflows in the TCP accept queue over the last minute + to: silent + +# THIS IS TOO GENERIC +# CHECK: https://github.com/netdata/netdata/issues/3234#issuecomment-423935842 + alarm: 1m_tcp_accept_queue_drops + on: ip.tcp_accept_queue + class: Workload + type: System +component: Network + os: linux + hosts: * + lookup: average -60s unaligned absolute of ListenDrops + units: drops + every: 10s + warn: $this > 1 + crit: $this > (($status == $CRITICAL) ? (1) : (5)) + delay: up 0 down 5m multiplier 1.5 max 1h + summary: System TCP accept queue dropped packets + info: Average number of dropped packets in the TCP accept queue over the last minute + to: silent + + +# ----------------------------------------------------------------------------- +# tcp SYN queue (at the kernel) + +# When the SYN queue is full, either TcpExtTCPReqQFullDoCookies or +# TcpExtTCPReqQFullDrop is incremented, depending on whether SYN cookies are +# enabled or not. In both cases this probably indicates a SYN flood attack, +# so i guess a notification should be sent. + + alarm: 1m_tcp_syn_queue_drops + on: ip.tcp_syn_queue + class: Workload + type: System +component: Network + os: linux + hosts: * + lookup: average -60s unaligned absolute of TCPReqQFullDrop + units: drops + every: 10s + warn: $this > 1 + crit: $this > (($status == $CRITICAL) ? (0) : (5)) + delay: up 10 down 5m multiplier 1.5 max 1h + summary: System TCP SYN queue drops + info: Average number of SYN requests was dropped due to the full TCP SYN queue over the last minute \ + (SYN cookies were not enabled) + to: silent + + alarm: 1m_tcp_syn_queue_cookies + on: ip.tcp_syn_queue + class: Workload + type: System +component: Network + os: linux + hosts: * + lookup: average -60s unaligned absolute of TCPReqQFullDoCookies + units: cookies + every: 10s + warn: $this > 1 + crit: $this > (($status == $CRITICAL) ? (0) : (5)) + delay: up 10 down 5m multiplier 1.5 max 1h + summary: System TCP SYN queue cookies + info: Average number of sent SYN cookies due to the full TCP SYN queue over the last minute + to: silent + |