Statistics

Listener

Every listener has a statistics tree rooted at listener.<address>. (or listener.<stat_prefix>. if stat_prefix is non-empty) with the following statistics:

Name	Type	Description
downstream_cx_total	Counter	Total connections
downstream_cx_destroy	Counter	Total destroyed connections
downstream_cx_active	Gauge	Total active connections
downstream_cx_length_ms	Histogram	Connection length milliseconds
downstream_cx_overflow	Counter	Total connections rejected due to enforcement of listener connection limit
downstream_cx_overload_reject	Counter	Total connections rejected due to configured overload actions
downstream_pre_cx_timeout	Counter	Sockets that timed out during listener filter processing
downstream_pre_cx_active	Gauge	Sockets currently undergoing listener filter processing
global_cx_overflow	Counter	Total connections rejected due to enforcement of the global connection limit
no_filter_chain_match	Counter	Total connections that didn’t match any filter chain

TLS statistics

The following TLS statistics are rooted at listener.<address>.ssl.:

Name	Type	Description
connection_error	Counter	Total TLS connection errors not including failed certificate verifications
handshake	Counter	Total successful TLS connection handshakes
session_reused	Counter	Total successful TLS session resumptions
no_certificate	Counter	Total successful TLS connections with no client certificate
fail_verify_no_cert	Counter	Total TLS connections that failed because of missing client certificate
fail_verify_error	Counter	Total TLS connections that failed CA verification
fail_verify_san	Counter	Total TLS connections that failed SAN verification
fail_verify_cert_hash	Counter	Total TLS connections that failed certificate pinning verification
ocsp_staple_failed	Counter	Total TLS connections that failed compliance with the OCSP policy
ocsp_staple_omitted	Counter	Total TLS connections that succeeded without stapling an OCSP response
ocsp_staple_responses	Counter	Total TLS connections where a valid OCSP response was available (irrespective of whether the client requested stapling)
ocsp_staple_requests	Counter	Total TLS connections where the client requested an OCSP staple
ciphers.<cipher>	Counter	Total successful TLS connections that used cipher <cipher>
curves.<curve>	Counter	Total successful TLS connections that used ECDHE curve <curve>
sigalgs.<sigalg>	Counter	Total successful TLS connections that used signature algorithm <sigalg>
versions.<version>	Counter	Total successful TLS connections that used protocol version <version>

UDP statistics

The following UDP statistics are available for UDP listeners and are rooted at listener.<address>.udp.:

Name	Type	Description
downstream_rx_datagram_dropped	Counter	Number of datagrams dropped due to kernel overflow or truncation

Per-handler Listener Stats

Every listener additionally has a statistics tree rooted at listener.<address>.<handler>. which contains per-handler statistics. As described in the threading model documentation, Envoy has a threading model which includes the main thread as well as a number of worker threads which are controlled by the --concurrency option. Along these lines, <handler> is equal to main_thread, worker_0, worker_1, etc. These statistics can be used to look for per-handler/worker imbalance on either accepted or active connections.

Name	Type	Description
downstream_cx_total	Counter	Total connections on this handler.
downstream_cx_active	Gauge	Total active connections on this handler.

Listener manager

The listener manager has a statistics tree rooted at listener_manager. with the following statistics. Any : character in the stats name is replaced with _.

Name	Type	Description
listener_added	Counter	Total listeners added (either via static config or LDS).
listener_modified	Counter	Total listeners modified (via LDS).
listener_removed	Counter	Total listeners removed (via LDS).
listener_stopped	Counter	Total listeners stopped.
listener_create_success	Counter	Total listener objects successfully added to workers.
listener_create_failure	Counter	Total failed listener object additions to workers.
listener_in_place_updated	Counter	Total listener objects created to execute filter chain update path.
total_filter_chains_draining	Gauge	Number of currently draining filter chains.
total_listeners_warming	Gauge	Number of currently warming listeners.
total_listeners_active	Gauge	Number of currently active listeners.
total_listeners_draining	Gauge	Number of currently draining listeners.
workers_started	Gauge	A boolean (1 if started and 0 otherwise) that indicates whether listeners have been initialized on workers.