What will happend if eviction_policy is set to "lru" but no capacity is set?
Article ID: KB0088795
Updated On:
| Products | Versions |
|---|---|
| TIBCO ActiveSpaces | - |
| Not Applicable | - |
Description
Resolution:
If space capacity is 1 million and if you're running with a total of 4 seeders, eviction starts once it reaches 4 million. LRU eviction policy always depends upon space (capacity * Number of SEEDERS).
Details regaarding how eviction_policy setup works.
If a put operation on a space would cause a seeder to exceed the space's capacity attribute, then the value of this attribute will dictate the result of the operation. If the value is 'none' (in quotes) then there will be no eviction and the operation will fail because the seeder is already at capacity. If the value is 'lru' (in quotes) then the seeder will evict another entry from the space using the 'least recently used' eviction algorithm. The default value is 'none' (no eviction).
If capacity is not set (meaning -1, NO capacity), eviction_policy does not matter.
When capacity is set with eviction policy none, capacity cannot be exceeded, and the put operation, unless it is an overwrite of an existing key, RU Capacity will be violated until necessary evictions are applied. Depending on key access (last recently used), entries would be evicted.
With HF12+ there is memory monitoring in place for the operating system while an AS node is running.When the AS process is about to run out of physical memory, AS will complain about memory usage and reject new puts. If this is something you are investigating, you would need to enable performance monitoring.
If space capacity is 1 million and if you're running with a total of 4 seeders, eviction starts once it reaches 4 million. LRU eviction policy always depends upon space (capacity * Number of SEEDERS).
Details regaarding how eviction_policy setup works.
If a put operation on a space would cause a seeder to exceed the space's capacity attribute, then the value of this attribute will dictate the result of the operation. If the value is 'none' (in quotes) then there will be no eviction and the operation will fail because the seeder is already at capacity. If the value is 'lru' (in quotes) then the seeder will evict another entry from the space using the 'least recently used' eviction algorithm. The default value is 'none' (no eviction).
If capacity is not set (meaning -1, NO capacity), eviction_policy does not matter.
When capacity is set with eviction policy none, capacity cannot be exceeded, and the put operation, unless it is an overwrite of an existing key, RU Capacity will be violated until necessary evictions are applied. Depending on key access (last recently used), entries would be evicted.
With HF12+ there is memory monitoring in place for the operating system while an AS node is running.When the AS process is about to run out of physical memory, AS will complain about memory usage and reject new puts. If this is something you are investigating, you would need to enable performance monitoring.
Issue/Introduction
What will happend if eviction_policy is set to "lru" but no capacity is set?
Additional Information
ActiveSpaces admin guide
Feedback
Yes
No
Powered by
