File Cache stores file contents in the memory. You can add an object to obj.conf to dynamically monitor and control the file cache while the server is running.
Add a NameTrans directive to the default object:
NameTrans fn="assign-name" from="/nsfc" name="nsfc"
Add an nsfc object definition:
<Object name="nsfc"> Service fn="service-nsfc-dump" </Object>
This configuration enables the file cache control and monitoring function (nsfc-dump) to be accessed through the URI /nfsc. To use a different URI, change the from parameter in the NameTrans directive.
The following is an example of the information you receive when you access the URI:
Sun Java System File Cache Status (pid 3602) The file cache is enabled. Cache resource utilization Number of cached file entries = 174968 (152 bytes each, 26595136 total bytes) Heap space used for cache = 1882632616/1882632760 bytes Mapped memory used for medium file contents = 0/1 bytes Number of cache lookup hits = 47615653/48089040 ( 99.02 %) Number of hits/misses on cached file info = 23720344/324195 Number of hits/misses on cached file content = 16247503/174985 Number of outdated cache entries deleted = 0 Number of cache entry replacements = 0 Total number of cache entries deleted = 0 Parameter settings ReplaceFiles: false ReplaceInterval: 1 milliseconds HitOrder: false CacheFileContent: true TransmitFile: false MaxAge: 3600 seconds MaxFiles: 600000 files SmallFileSizeLimit: 500000 bytes MediumFileSizeLimit: 1000001 bytes BufferSize: 8192 bytes CopyFiles: false Directory for temporary files: /tmp Hash table size: 1200007 buckets |
You can include a query string when you access the URI. The following values are recognized:
?list: Lists the files in the cache.
?refresh=n: Causes the client to reload the page every n seconds.
?restart: Causes the cache to be shut down and then restarted.
?start: Starts the cache.
?stop: Shuts down the cache.
If you choose the ?list option, the file listing includes the file name, a set of flags, the current number of references to the cache entry, the size of the file, and an internal file ID value. The flags are as follows:
C: File contents are cached.
D: Cache entry is marked for delete.
I: File information including size and modification date is cached.
M: File contents are mapped into virtual memory.
O: File descriptor is cached (when TransmitFile is set to true).
P: File has associated private data and appears on shtml files.
T: Cache entry has a temporary file.
W: Cache entry is locked for write access.