Statistics

Every connection manager has a statistics tree rooted at http.<stat_prefix>. with the following statistics:

Name

Type

Description

downstream_cx_total

Counter

Total connections

downstream_cx_ssl_total

Counter

Total TLS connections

downstream_cx_http1_total

Counter

Total HTTP/1.1 connections

downstream_cx_upgrades_total

Counter

Total successfully upgraded connections. These are also counted as total http1/http2 connections.

downstream_cx_http2_total

Counter

Total HTTP/2 connections

downstream_cx_destroy

Counter

Total connections destroyed

downstream_cx_destroy_remote

Counter

Total connections destroyed due to remote close

downstream_cx_destroy_local

Counter

Total connections destroyed due to local close

downstream_cx_destroy_active_rq

Counter

Total connections destroyed with 1+ active request

downstream_cx_destroy_local_active_rq

Counter

Total connections destroyed locally with 1+ active request

downstream_cx_destroy_remote_active_rq

Counter

Total connections destroyed remotely with 1+ active request

downstream_cx_active

Gauge

Total active connections

downstream_cx_ssl_active

Gauge

Total active TLS connections

downstream_cx_http1_active

Gauge

Total active HTTP/1.1 connections

downstream_cx_upgrades_active

Gauge

Total active upgraded connections. These are also counted as active http1/http2 connections.

downstream_cx_http2_active

Gauge

Total active HTTP/2 connections

downstream_cx_protocol_error

Counter

Total protocol errors

downstream_cx_length_ms

Histogram

Connection length milliseconds

downstream_cx_rx_bytes_total

Counter

Total bytes received

downstream_cx_rx_bytes_buffered

Gauge

Total received bytes currently buffered

downstream_cx_tx_bytes_total

Counter

Total bytes sent

downstream_cx_tx_bytes_buffered

Gauge

Total sent bytes currently buffered

downstream_cx_drain_close

Counter

Total connections closed due to draining

downstream_cx_idle_timeout

Counter

Total connections closed due to idle timeout

downstream_cx_max_duration_reached

Counter

Total connections closed due to max connection duration

downstream_cx_overload_disable_keepalive

Counter

Total connections for which HTTP 1.x keepalive has been disabled due to Envoy overload

downstream_flow_control_paused_reading_total

Counter

Total number of times reads were disabled due to flow control

downstream_flow_control_resumed_reading_total

Counter

Total number of times reads were enabled on the connection due to flow control

downstream_rq_total

Counter

Total requests

downstream_rq_http1_total

Counter

Total HTTP/1.1 requests

downstream_rq_http2_total

Counter

Total HTTP/2 requests

downstream_rq_active

Gauge

Total active requests

downstream_rq_response_before_rq_complete

Counter

Total responses sent before the request was complete

downstream_rq_rx_reset

Counter

Total request resets received

downstream_rq_tx_reset

Counter

Total request resets sent

downstream_rq_non_relative_path

Counter

Total requests with a non-relative HTTP path

downstream_rq_too_large

Counter

Total requests resulting in a 413 due to buffering an overly large body

downstream_rq_completed

Counter

Total requests that resulted in a response (e.g. does not include aborted requests)

downstream_rq_1xx

Counter

Total 1xx responses

downstream_rq_2xx

Counter

Total 2xx responses

downstream_rq_3xx

Counter

Total 3xx responses

downstream_rq_4xx

Counter

Total 4xx responses

downstream_rq_5xx

Counter

Total 5xx responses

downstream_rq_ws_on_non_ws_route

Counter

Total upgrade requests rejected by non upgrade routes. This now applies both to WebSocket and non-WebSocket upgrades

downstream_rq_time

Histogram

Total time for request and response (milliseconds)

downstream_rq_idle_timeout

Counter

Total requests closed due to idle timeout

downstream_rq_max_duration_reached

Counter

Total requests closed due to max duration reached

downstream_rq_timeout

Counter

Total requests closed due to a timeout on the request path

downstream_rq_overload_close

Counter

Total requests closed due to Envoy overload

rs_too_large

Counter

Total response errors due to buffering an overly large body

Per user agent statistics

Additional per user agent statistics are rooted at http.<stat_prefix>.user_agent.<user_agent>. Currently Envoy matches user agent for both iOS (ios) and Android (android) and produces the following statistics:

Name

Type

Description

downstream_cx_total

Counter

Total connections

downstream_cx_destroy_remote_active_rq

Counter

Total connections destroyed remotely with 1+ active requests

downstream_rq_total

Counter

Total requests

Per listener statistics

Additional per listener statistics are rooted at listener.<address>.http.<stat_prefix>. with the following statistics:

Name

Type

Description

downstream_rq_completed

Counter

Total responses

downstream_rq_1xx

Counter

Total 1xx responses

downstream_rq_2xx

Counter

Total 2xx responses

downstream_rq_3xx

Counter

Total 3xx responses

downstream_rq_4xx

Counter

Total 4xx responses

downstream_rq_5xx

Counter

Total 5xx responses

Per codec statistics

Each codec has the option of adding per-codec statistics. Both http1 and http2 have codec stats.

Http1 codec statistics

All http1 statistics are rooted at http1.

Name

Type

Description

dropped_headers_with_underscores

Counter

Total number of dropped headers with names containing underscores. This action is configured by setting the headers_with_underscores_action config setting.

metadata_not_supported_error

Counter

Total number of metadata dropped during HTTP/1 encoding

response_flood

Counter

Total number of connections closed due to response flooding

requests_rejected_with_underscores_in_headers

Counter

Total numbers of rejected requests due to header names containing underscores. This action is configured by setting the headers_with_underscores_action config setting.

Http2 codec statistics

All http2 statistics are rooted at http2.

Name

Type

Description

dropped_headers_with_underscores

Counter

Total number of dropped headers with names containing underscores. This action is configured by setting the headers_with_underscores_action config setting.

header_overflow

Counter

Total number of connections reset due to the headers being larger than the configured value.

headers_cb_no_stream

Counter

Total number of errors where a header callback is called without an associated stream. This tracks an unexpected occurrence due to an as yet undiagnosed bug

inbound_empty_frames_flood

Counter

Total number of connections terminated for exceeding the limit on consecutive inbound frames with an empty payload and no end stream flag. The limit is configured by setting the max_consecutive_inbound_frames_with_empty_payload config setting.

inbound_priority_frames_flood

Counter

Total number of connections terminated for exceeding the limit on inbound frames of type PRIORITY. The limit is configured by setting the max_inbound_priority_frames_per_stream config setting.

inbound_window_update_frames_flood

Counter

Total number of connections terminated for exceeding the limit on inbound frames of type WINDOW_UPDATE. The limit is configured by setting the max_inbound_window_updateframes_per_data_frame_sent config setting.

outbound_flood

Counter

Total number of connections terminated for exceeding the limit on outbound frames of all types. The limit is configured by setting the max_outbound_frames config setting.

outbound_control_flood

Counter

Total number of connections terminated for exceeding the limit on outbound frames of types PING, SETTINGS and RST_STREAM. The limit is configured by setting the max_outbound_control_frames config setting.

requests_rejected_with_underscores_in_headers

Counter

Total numbers of rejected requests due to header names containing underscores. This action is configured by setting the headers_with_underscores_action config setting.

rx_messaging_error

Counter

Total number of invalid received frames that violated section 8 of the HTTP/2 spec. This will result in a tx_reset

rx_reset

Counter

Total number of reset stream frames received by Envoy

trailers

Counter

Total number of trailers seen on requests coming from downstream

tx_flush_timeout

Counter

Total number of stream idle timeouts waiting for open stream window to flush the remainder of a stream

tx_reset

Counter

Total number of reset stream frames transmitted by Envoy

streams_active

Gauge

Active streams as observed by the codec

pending_send_bytes

Gauge

Currently buffered body data in bytes waiting to be written when stream/connection window is opened.

Attention

The HTTP/2 streams_active gauge may be greater than the HTTP connection manager downstream_rq_active gauge due to differences in stream accounting between the codec and the HTTP connection manager.

Tracing statistics

Tracing statistics are emitted when tracing decisions are made. All tracing statistics are rooted at http.<stat_prefix>.tracing. with the following statistics:

Name

Type

Description

random_sampling

Counter

Total number of traceable decisions by random sampling

service_forced

Counter

Total number of traceable decisions by server runtime flag tracing.global_enabled

client_enabled

Counter

Total number of traceable decisions by request header x-envoy-force-trace

not_traceable

Counter

Total number of non-traceable decisions by request id

health_check

Counter

Total number of non-traceable decisions by health check