memory (instance statistics)

AMPS can provide information regarding the process’s memory usage in its RSS and VMSize via the memory resource in the monitoring interface.

Metric	Description	Type
`caches`	Information about AMPS memory caches.	(see caches)
`paginations`	Information about paginated result sets.	(see paginations)
`rss`	The resident set size of the AMPS process.	snapshot
`vmsize`	The virtual memory size of the AMPS process.	snapshot

Statistics Database Tables: IMEMORY_STATIC, IMEMORY_DYNAMIC, IMEMORY_CACHES_STATIC, IMEMORY_CACHES_DYNAMIC

Admin Paths:

The caches element provides information about currently-active memory caches.

Metric	Description	Type
`allocations`	Number of memory allocations for this cache.	cumulative
`bytes`	Number of bytes allocated to this cache.	snapshot
`description`	Description of the cache.	fixed
`efficiency`	Cache efficiency ratio. Higher values indicate greater cache efficiency (cache reuse or storage utilization).	snapshot
`entries`	Number of entries in this cache.	snapshot
`evictions`	Count of evictions from this cache.	cumulative
`fetches`	Count of fetches from this cache.	cumulative
`overflow_bytes`	Current bytes of allocated storage reported by this cache's allocator. This value may decrease when storage is released and does not exclusively represent memory used for slow consumers.	snapshot

The following caches may appear in AMPS statistics:

Cache Name	Description
`byte buffer cache`	General purpose cache.
`byte in buffer cache`	Cache for bytes being received from clients.
`byte out buffer cache`	Cache for bytes being sent to clients.
`client cache`	Cache for client objects.
`client entitlement cache`	Cache for maintaining entitlement information.
`client session cache`	Cache for maintaining current session state.
`client status cache`	Cache for forming client status messages.
`message cache`	Cache for message objects.
`query context cache`	Cache for query contexts.
`sow update cache`	Cache for SOW updates.
`subscription cache`	Cache for subscription state.
`xpath value data buffer cache`	Cache for XPath values.

Statistics Database Table: IMEMORY_CACHES

The paginations element provides information about currently-active paginated subscriptions in AMPS.

Metric	Description	Type
`memory_bytes`	Number of bytes consumed to maintain this paginated set.	snapshot
`message_type`	Message type for this paginated set.	fixed
`subscription_count`	Number of subscriptions using this paginated set.	snapshot
`topic`	Source topic for this paginated set.	fixed

Statistics Database Table: IPAGINATIONS