Cache properties

Modified on Thu, 2 Nov, 2023 at 1:02 PM

The cache.properties file offers setting options for caching forms and files.

There are two types of caches:

The form cache stores the rendered HTML web forms created with FORMCYCLE.
The file cache stores files used by the system, such as attachments and form files.

There are three types of cache storage: on-heap, off-heap, disk.

On-heap storage is the fastest way of storing data. It stores Java objects directly in the Java on-heap, which is part of the system's RAM storage. However, as objects are not serialized, it is not possible to specifiy an upper size limit for this type of cache. By default, this type of cache is disabled. If performance is an issue, consider disabling the off-heap storage and enable the on-heap storage instead. Use the JVM parameter -Xmx396m to change the maximum size of the on-heap.
Off-heap storage also uses the RAM, but serializes Java objects and stores the serialized data in the Java off-heap. This type of cache is still fast, but slightly slower due to the extra overhead of serialization. Unlike the on-heap storage, however, this type of storage lets you specify a size limit. Note that the Java off-heap can be configured separately from the Java on-heap. Most Java virtual machine implementations default the off-heap size to the same value as the on-heap size. You can use the JVM parameter -XX:MaxDirectMemorySize=3G to change the off-heap size.
Disk storage is the slowest method of storing data. It serializes Java objects and stores them in a file on the file-system. The main advantage of the disk storage is its large capacity.

formcycle uses a tiered approach. New cache entries are stored in the the fastest type of storage. Older entries are moved to slower storage types when the limit of the faster cache storage is reached.

Property	Default value	Explanation
cache.generic.disk.size	-1	Maximum size in MB of what the file cache stores in the file system. No limit when set to -1. If set to 0, the file system is not used by the cache.
cache.generic.heap.size	75	Maximum size in MB of the file cache's size in the Java off-heap.
cache.generic.onheap.entries	-1	Maximum number of entries in the the file cache's on-heap storage.
cache.generic.idletime	0	Time interval in seconds until an item in the form cache is removed when it is never accessed during that time interval. Set to 0 to disable.
cache.forms.disk.size	-1	Maximum size in MB of the form cache's size on the file system . No limit when set to -1. If set to 0, the file system is not used by the cache.
cache.forms.heap.size	75	Maximum size in MB of the form cache's size in the Java off-heap.
cache.forms.onheap.entries	-1	Maximum number of entries in the the form cache's on-heap storage.
cache.forms.idletime	0	Time interval in seconds until an item in the form cache is removed when it is never accessed during that time interval. Set to 0 to disable.
cache.license.disk.size	100	Maximum size in MB of what the file cache stores in the file system. No limit when set to -1. If set to 0, the file system is not used by the cache.
cache.license.heap.size	20	Maximum size in MB of the file cache's size in the Java off-heap.
cache.license.idletime.size	36000	Time interval in seconds until an item in the form cache is removed when it is never accessed during that time interval. Set to 0 to disable.