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Monitoring Stash

Stash has native support for monitoring via Prometheus. You can use builtin Prometheus scraper or CoreOS Prometheus Operator to monitor Stash. This tutorial will show you how this monitoring works with Stash and how to enable them.

Overview

Stash uses Prometheus PushGateway to export the metrics for backup & restore operations. Following diagram shows the logical structure of Stash monitoring flow.

  Stash Monitoring Flow
Fig: Monitoring process in Stash

Stash operator runs two containers. The operator container runs controller and other necessary stuffs and the pushgateway container runs prom/pushgateway image. Stash sidecar from different workloads pushes its metrics to this pushgateway. Then Prometheus server scrapes these metrics through stash-operator service. Stash operator itself also provides some metrics at /metrics path of :8443 port.

Backup Metrics

Following metrics available for backup process:

Metric Uses
stash_backup_setup_success Indicates whether backup was successfully setup for the target
stash_backup_session_success Indicates whether the current backup session succeeded or not
stash_backup_session_duration_total_seconds Total time taken to complete the backup session
stash_backup_data_size_bytes Total size of the target data to backup (in bytes)
stash_backup_data_uploaded_bytes Amount of data uploaded to the repository in this session (in bytes)
stash_backup_data_processing_time_seconds Total time taken to backup the target data
stash_backup_files_total Total number of files that has been backed up
stash_backup_files_new Total number of new files that has been created since last backup
stash_backup_files_modified Total number of files that has been modified since last backup
stash_backup_files_unmodified Total number of files that has not been changed since last backup

Repository Metrics

Following metrics are available for backup repository:

Metric Uses
stash_repository_integrity Result of repository integrity check after last backup
stash_repository_size_bytes Indicates size of repository after last backup (in bytes)
stash_repository_snapshot_count Indicates number of snapshots stored in the repository
stash_repository_snapshot_cleaned Indicates number of old snapshots cleaned up according to retention policy on last backup session

Restore Metrics

Following metrics are available for restore process:

Metric Uses
stash_restore_session_success Result of repository integrity check after last backup
stash_restore_session_duration_total_seconds Indicates size of repository after last backup (in bytes)

Operator Metrics

Following metrics are available for Stash operator. These metrics are accessible through api endpoint of stash-operator service.

API Server Metrics:

Metric Name Uses
apiserver_audit_event_total Counter of audit events generated and sent to the audit backend.
apiserver_client_certificate_expiration_seconds Distribution of the remaining lifetime on the certificate used to authenticate a request.
apiserver_current_inflight_requests Maximal number of currently used inflight request limit of this apiserver per request kind in last second.
apiserver_request_count Counter of apiserver requests broken out for each verb, API resource, client, and HTTP response contentType and code.
apiserver_request_latencies Response latency distribution in microseconds for each verb, resource and subresource.
apiserver_request_latencies_summary Response latency summary in microseconds for each verb, resource and subresource.
authenticated_user_requests Counter of authenticated requests broken out by username.

Go Metrics:

Metric Name Uses
go_gc_duration_seconds A summary of the GC invocation durations.
go_goroutines Number of goroutines that currently exist.
go_memstats_alloc_bytes Number of bytes allocated and still in use.
go_memstats_alloc_bytes_total Total number of bytes allocated, even if freed.
go_memstats_buck_hash_sys_bytes Number of bytes used by the profiling bucket hash table.
go_memstats_frees_total Total number of frees.
go_memstats_gc_sys_bytes Number of bytes used for garbage collection system metadata.
go_memstats_heap_alloc_bytes Number of heap bytes allocated and still in use.
go_memstats_heap_idle_bytes Number of heap bytes waiting to be used.
go_memstats_heap_inuse_bytes Number of heap bytes that are in use.
go_memstats_heap_objects Number of allocated objects.
go_memstats_heap_released_bytes_total Total number of heap bytes released to OS.
go_memstats_heap_sys_bytes Number of heap bytes obtained from system.
go_memstats_last_gc_time_seconds Number of seconds since 1970 of last garbage collection.
go_memstats_lookups_total Total number of pointer lookups.
go_memstats_mallocs_total Total number of mallocs.
go_memstats_mcache_inuse_bytes Number of bytes in use by mcache structures.
go_memstats_mcache_sys_bytes Number of bytes used for mcache structures obtained from system.
go_memstats_mspan_inuse_bytes Number of bytes in use by mspan structures.
go_memstats_mspan_sys_bytes Number of bytes used for mspan structures obtained from system.
go_memstats_next_gc_bytes Number of heap bytes when next garbage collection will take place.
go_memstats_other_sys_bytes Number of bytes used for other system allocations.
go_memstats_stack_inuse_bytes Number of bytes in use by the stack allocator.
go_memstats_stack_sys_bytes Number of bytes obtained from system for stack allocator.
go_memstats_sys_bytes Number of bytes obtained by system. Sum of all system allocations.

HTTP Metrics:

Metrics Uses
http_request_duration_microseconds The HTTP request latencies in microseconds.
http_request_size_bytes The HTTP request sizes in bytes.
http_requests_total Total number of HTTP requests made.
http_response_size_bytes The HTTP response sizes in bytes.

Process Metrics:

Metric Name Uses
process_cpu_seconds_total Total user and system CPU time spent in seconds.
process_max_fds Maximum number of open file descriptors.
process_open_fds Number of open file descriptors.
process_resident_memory_bytes Resident memory size in bytes.
process_start_time_seconds Start time of the process since unix epoch in seconds.
process_virtual_memory_bytes Virtual memory size in bytes.

How to Enable Monitoring

You can enable monitoring through some flags while installing or upgrading or updating Stash via both script and Helm. You can also chose which monitoring agent to use for monitoring. Stash will configure respective resources accordingly. Here, are the list of available flags and their uses,

Script Flag Helm Values Acceptable Values Default Uses
--monitoring-agent monitoring.agent prometheus.io/builtin or prometheus.io/coreos-operator none Specify which monitoring agent to use for monitoring Stash.
--monitoring-backup monitoring.backup true or false false Specify whether to monitor Stash backup and restore.
--monitoring-operator monitoring.operator true or false false Specify whether to monitor Stash operator.
--prometheus-namespace monitoring.prometheus.namespace any namespace same namespace as Stash operator Specify the namespace where Prometheus server is running or will be deployed
--servicemonitor-label monitoring.serviceMonitor.labels any label For Helm installation, app: <generated app name> and release: <release name>. For script installation, app: stash Specify the labels for ServiceMonitor. Prometheus crd will select ServiceMonitor using these labels. Only usable when monitoring agent is prometheus.io/coreos-operator.

You have to provides these flags while installing or upgrading or updating Stash. Here, are examples for both script and Helm installation process are given which enable monitoring with prometheus.io/coreos-operator Prometheuse server for backup, restore and operator metrics.

Helm:

$ helm install appscode/stash --name stash-operator --version v0.9.0-rc.0 --namespace kube-system \
  --set monitoring.agent=prometheus.io/coreos-operator \
  --set monitoring.backup=true \
  --set monitoring.operator=true \
  --set monitoring.prometheus.namespace=monitoring \
  --set monitoring.serviceMonitor.labels.k8s-app=prometheus

Script:

$ curl -fsSL https://github.com/stashed/installer/raw/v0.9.0-rc.0/deploy/stash.sh  | bash -s -- \
  --monitoring-agent=prometheus.io/coreos-operator \
  --monitoring-backup=true \
  --monitoring-operator=true \
  --prometheus-namespace=monitoring \
  --servicemonitor-label=k8s-app=prometheus

Next Steps

  • Learn how to monitor Stash using built-in Prometheus from here.
  • Learn how to monitor Stash using CoreOS Prometheus operator from here.