8.7.5. REST Interface Operation Headers
8.7.5.1. Headers
The following table displays headers that are included in the JBoss Data Grid REST Interface:
| Headers | Mandatory/Optional | Values | Default Value | Details |
|---|---|---|---|---|
| Content-Type | Mandatory | - | - | If the Content-Type is set to application/x-java-serialized-object, it is stored as a Java object. |
| performAsync | Optional | True/False | - | If set to true, an immediate return occurs, followed by a replication of data to the cluster on its own. This feature is useful when dealing with bulk data inserts and large clusters. |
| timeToLiveSeconds | Optional | Numeric (positive and negative numbers) | -1 (This value prevents expiration as a direct result of timeToLiveSeconds. Expiration values set elsewhere override this default value.) | Reflects the number of seconds before the entry in question is automatically deleted. Setting a negative value for timeToLiveSeconds provides the same result as the default value. |
| maxIdleTimeSeconds | Optional | Numeric (positive and negative numbers) | -1 (This value prevents expiration as a direct result of maxIdleTimeSeconds. Expiration values set elsewhere override this default value.) | Contains the number of seconds after the last usage when the entry will be automatically deleted. Passing a negative value provides the same result as the default value. |
The following combinations can be set for the
timeToLiveSeconds and maxIdleTimeSeconds headers:
- If both the
timeToLiveSecondsandmaxIdleTimeSecondsheaders are assigned the value0, the cache uses the defaulttimeToLiveSecondsandmaxIdleTimeSecondsvalues configured either using XML or programatically. - If only the
maxIdleTimeSecondsheader value is set to0, thetimeToLiveSecondsvalue should be passed as the parameter (or the default-1, if the parameter is not present). Additionally, themaxIdleTimeSecondsparameter value defaults to the values configured either using XML or programatically. - If only the
timeToLiveSecondsheader value is set to0, expiration occurs immediately and themaxIdleTimeSecondsvalue is set to the value passed as a parameter (or the default-1if no parameter was supplied).
ETag Based Headers
ETags (Entity Tags) are returned for each REST Interface entry, along with a Last-Modified header that indicates the state of the data at the supplied URL. ETags are used in HTTP operations to request data exclusively in cases where the data has changed to save bandwidth. The following headers support ETags (Entity Tags) based optimistic locking:
| Header | Algorithm | Example | Details |
|---|---|---|---|
| If-Match | If-Match = "If-Match" ":" ( "*" | 1#entity-tag ) | - | Used in conjunction with a list of associated entity tags to verify that a specified entity (that was previously obtained from a resource) remains current. |
| If-None-Match | - | Used in conjunction with a list of associated entity tags to verify that none of the specified entities (that was previously obtained from a resource) are current. This feature facilitates efficient updates of cached information when required and with minimal transaction overhead. | |
| If-Modified-Since | If-Modified-Since = "If-Modified-Since" ":" HTTP-date | If-Modified-Since: Sat, 29 Oct 1994 19:43:31 GMT | Compares the requested variant's last modification time and date with a supplied time and date value. If the requested variant has not been modified since the specified time and date, a 304 (not modified) response is returned without a message-body instead of an entity. |
| If-Unmodified-Since | If-Unmodified-Since = "If-Unmodified-Since" ":" HTTP-date | If-Unmodified-Since: Sat, 29 Oct 1994 19:43:31 GMT | Compares the requested variant's last modification time and date with a supplied time and date value. If the requested resources has not been modified since the supplied date and time, the specified operation is performed. If the requested resource has been modified since the supplied date and time, the operation is not performed and a 412 (Precondition Failed) response is returned. |
