Statistics

A few statistics are emitted to report statistics system behavior:

NameTypeDescription
stats.overflowCounterTotal number of times Envoy cannot allocate a statistic due to a shortage of shared memory

Server

Server related statistics are rooted at server. with following statistics:

NameTypeDescription
uptimeGaugeCurrent server uptime in seconds
concurrencyGaugeNumber of worker threads
memory_allocatedGaugeCurrent amount of allocated memory in bytes. Total of both new and old Envoy processes on hot restart.
memory_heap_sizeGaugeCurrent reserved heap size in bytes. New Envoy process heap size on hot restart.
liveGauge1 if the server is not currently draining, 0 otherwise
parent_connectionsGaugeTotal connections of the old Envoy process on hot restart
total_connectionsGaugeTotal connections of both new and old Envoy processes
versionGaugeInteger represented version number based on SCM revision
days_until_first_cert_expiringGaugeNumber of days until the next certificate being managed will expire
hot_restart_epochGaugeCurrent hot restart epoch

File system

Statistics related to file system are emitted in the filesystem. namespace.

NameTypeDescription
write_bufferedCounterTotal number of times file data is moved to Envoy’s internal flush buffer
write_completedCounterTotal number of times a file was written
flushed_by_timerCounterTotal number of times internal flush buffers are written to a file due to flush timeout
reopen_failedCounterTotal number of times a file was failed to be opened
write_total_bufferedGaugeCurrent total size of internal flush buffer in bytes