minio/docs/caching
Harshavardhana 716316f711 Reduce number of envs and options from command line. (#3230)
Ref #3229

After review with @abperiasamy we decided to remove all the unnecessary options

- MINIO_BROWSER (Implemented as a security feature but now deemed obsolete
  since even if blocking access to MINIO_BROWSER, s3 API port is open)
- MINIO_CACHE_EXPIRY (Defaults to 72h)
- MINIO_MAXCONN (No one used this option and we don't test this)
- MINIO_ENABLE_FSMETA (Enable FSMETA all the time)

Remove --ignore-disks option - this option was implemented when XL layer
 would initialize the backend disks and heal them automatically to disallow
 XL accidentally using the root partition itself this option was introduced.

This behavior has been changed XL no longer automatically initializes
`format.json`  a HEAL is controlled activity, so ignore-disks is not
useful anymore. This change also addresses the problems of our documentation
going forward and keeps things simple. This patch brings in reduction of
options and defaulting them to a valid known inputs.  This patch also
serves as a guideline of limiting many ways to do the same thing.
2016-11-11 16:40:55 -08:00
..
README.md Reduce number of envs and options from command line. (#3230) 2016-11-11 16:40:55 -08:00

Object caching

Object caching by turned on by default with following settings

  • Default cache size 8GB. Cache size also automatically picks a lower value if your local memory size is lower than 8GB.

  • Default expiration of entries happensat 72 hours, this option cannot be changed.

  • Default expiry interval is 1/4th of the expiration hours, so expiration sweep happens across the cache every 1/4th the time duration of the set entry expiration duration.

Behavior

Caching happens on both GET and PUT operations.

  • GET caches new objects for entries not found in cache.

  • PUT/POST caches all successfully uploaded objects.

In all other cases if objects are served from cache.

NOTE:

Cache is always populated upon object is successfully read from the disk.

Expiration happens automatically based on the configured interval as explained above, frequently accessed objects stay alive for significantly longer time due to the fact that expiration time is reset for every cache hit.