loki cache_config

The cache block configures the cache backend. The supported CLI flags <prefix> used to reference this configuration block are:

• frontend
• frontend.index-stats-results-cache
• store.chunks-cache
• store.index-cache-read
• store.index-cache-write

# (deprecated: use embedded-cache instead) Enable in-memory cache (auto-enabled
# for the chunks & query results cache if no other cache is configured).
# CLI flag: -<prefix>.cache.enable-fifocache
[enable_fifocache: <boolean> | default = false]

# The default validity of entries for caches unless overridden.
# CLI flag: -<prefix>.default-validity
[default_validity: <duration> | default = 1h]

background:
  # At what concurrency to write back to cache.
  # CLI flag: -<prefix>.background.write-back-concurrency
  [writeback_goroutines: <int> | default = 10]

  # How many key batches to buffer for background write-back.
  # CLI flag: -<prefix>.background.write-back-buffer
  [writeback_buffer: <int> | default = 10000]

  # Size limit in bytes for background write-back.
  # CLI flag: -<prefix>.background.write-back-size-limit
  [writeback_size_limit: <int> | default = 1GB]

memcached:
  # How long keys stay in the memcache.
  # CLI flag: -<prefix>.memcached.expiration
  [expiration: <duration> | default = 0s]

  # How many keys to fetch in each batch.
  # CLI flag: -<prefix>.memcached.batchsize
  [batch_size: <int> | default = 1024]

  # Maximum active requests to memcache.
  # CLI flag: -<prefix>.memcached.parallelism
  [parallelism: <int> | default = 100]

memcached_client:
  # Hostname for memcached service to use. If empty and if addresses is unset,
  # no memcached will be used.
  # CLI flag: -<prefix>.memcached.hostname
  [host: <string> | default = ""]

  # SRV service used to discover memcache servers.
  # CLI flag: -<prefix>.memcached.service
  [service: <string> | default = "memcached"]

  # EXPERIMENTAL: Comma separated addresses list in DNS Service Discovery
  # format:
  # https://cortexmetrics.io/docs/configuration/arguments/#dns-service-discovery
  # CLI flag: -<prefix>.memcached.addresses
  [addresses: <string> | default = ""]

  # Maximum time to wait before giving up on memcached requests.
  # CLI flag: -<prefix>.memcached.timeout
  [timeout: <duration> | default = 100ms]

  # Maximum number of idle connections in pool.
  # CLI flag: -<prefix>.memcached.max-idle-conns
  [max_idle_conns: <int> | default = 16]

  # The maximum size of an item stored in memcached. Bigger items are not
  # stored. If set to 0, no maximum size is enforced.
  # CLI flag: -<prefix>.memcached.max-item-size
  [max_item_size: <int> | default = 0]

  # Period with which to poll DNS for memcache servers.
  # CLI flag: -<prefix>.memcached.update-interval
  [update_interval: <duration> | default = 1m]

  # Use consistent hashing to distribute to memcache servers.
  # CLI flag: -<prefix>.memcached.consistent-hash
  [consistent_hash: <boolean> | default = true]

  # Trip circuit-breaker after this number of consecutive dial failures (if zero
  # then circuit-breaker is disabled).
  # CLI flag: -<prefix>.memcached.circuit-breaker-consecutive-failures
  [circuit_breaker_consecutive_failures: <int> | default = 10]

  # Duration circuit-breaker remains open after tripping (if zero then 60
  # seconds is used).
  # CLI flag: -<prefix>.memcached.circuit-breaker-timeout
  [circuit_breaker_timeout: <duration> | default = 10s]

  # Reset circuit-breaker counts after this long (if zero then never reset).
  # CLI flag: -<prefix>.memcached.circuit-breaker-interval
  [circuit_breaker_interval: <duration> | default = 10s]

redis:
  # Redis Server or Cluster configuration endpoint to use for caching. A
  # comma-separated list of endpoints for Redis Cluster or Redis Sentinel. If
  # empty, no redis will be used.
  # CLI flag: -<prefix>.redis.endpoint
  [endpoint: <string> | default = ""]

  # Redis Sentinel master name. An empty string for Redis Server or Redis
  # Cluster.
  # CLI flag: -<prefix>.redis.master-name
  [master_name: <string> | default = ""]

  # Maximum time to wait before giving up on redis requests.
  # CLI flag: -<prefix>.redis.timeout
  [timeout: <duration> | default = 500ms]

  # How long keys stay in the redis.
  # CLI flag: -<prefix>.redis.expiration
  [expiration: <duration> | default = 0s]

  # Database index.
  # CLI flag: -<prefix>.redis.db
  [db: <int> | default = 0]

  # Maximum number of connections in the pool.
  # CLI flag: -<prefix>.redis.pool-size
  [pool_size: <int> | default = 0]

  # Username to use when connecting to redis.
  # CLI flag: -<prefix>.redis.username
  [username: <string> | default = ""]

  # Password to use when connecting to redis.
  # CLI flag: -<prefix>.redis.password
  [password: <string> | default = ""]

  # Enable connecting to redis with TLS.
  # CLI flag: -<prefix>.redis.tls-enabled
  [tls_enabled: <boolean> | default = false]

  # Skip validating server certificate.
  # CLI flag: -<prefix>.redis.tls-insecure-skip-verify
  [tls_insecure_skip_verify: <boolean> | default = false]

  # Close connections after remaining idle for this duration. If the value is
  # zero, then idle connections are not closed.
  # CLI flag: -<prefix>.redis.idle-timeout
  [idle_timeout: <duration> | default = 0s]

  # Close connections older than this duration. If the value is zero, then the
  # pool does not close connections based on age.
  # CLI flag: -<prefix>.redis.max-connection-age
  [max_connection_age: <duration> | default = 0s]

  # By default, the Redis client only reads from the master node. Enabling this
  # option can lower pressure on the master node by randomly routing read-only
  # commands to the master and any available replicas.
  # CLI flag: -<prefix>.redis.route-randomly
  [route_randomly: <boolean> | default = false]

embedded_cache:
  # Whether embedded cache is enabled.
  # CLI flag: -<prefix>.embedded-cache.enabled
  [enabled: <boolean> | default = false]

  # Maximum memory size of the cache in MB.
  # CLI flag: -<prefix>.embedded-cache.max-size-mb
  [max_size_mb: <int> | default = 100]

  # The time to live for items in the cache before they get purged.
  # CLI flag: -<prefix>.embedded-cache.ttl
  [ttl: <duration> | default = 1h]

fifocache:
  # Maximum memory size of the cache in bytes. A unit suffix (KB, MB, GB) may be
  # applied.
  # CLI flag: -<prefix>.fifocache.max-size-bytes
  [max_size_bytes: <string> | default = "1GB"]

  # deprecated: Maximum number of entries in the cache.
  # CLI flag: -<prefix>.fifocache.max-size-items
  [max_size_items: <int> | default = 0]

  # The time to live for items in the cache before they get purged.
  # CLI flag: -<prefix>.fifocache.ttl
  [ttl: <duration> | default = 1h]

  # Deprecated (use ttl instead): The expiry duration for the cache.
  # CLI flag: -<prefix>.fifocache.duration
  [validity: <duration> | default = 0s]

  # Deprecated (use max-size-items or max-size-bytes instead): The number of
  # entries to cache.
  # CLI flag: -<prefix>.fifocache.size
  [size: <int> | default = 0]

  [purgeinterval: <duration>]

# The maximum number of concurrent asynchronous writeback cache can occur.
# CLI flag: -<prefix>.max-async-cache-write-back-concurrency
[async_cache_write_back_concurrency: <int> | default = 16]

# The maximum number of enqueued asynchronous writeback cache allowed.
# CLI flag: -<prefix>.max-async-cache-write-back-buffer-size
[async_cache_write_back_buffer_size: <int> | default = 500]