Hi,
I am preparing a patch for https://issues.apache.org/jira/browse/BOOKKEEPER-827
, in which try to turn maxOutstandingRequests from "by entries" to "by bytes".
while reading the part of comments at the front of
setCompactionMaxOutstandingRequests(), it makes me a little confusing:
"A higher value for this parameter means more memory will be used for offsets"
<=== here, I thought the memory should mainly be occupied by the entries that
added into "FileChannel", but not flushed. right?
bookkeeper-server/src/main/java/org/apache/bookkeeper/conf/ServerConfiguration.java
: line 1231
------------------------
/**
* Set the maximum number of entries which can be compacted without
flushing.
*
* When compacting, the entries are written to the entrylog and the new
offsets
* are cached in memory. Once the entrylog is flushed the index is updated
with
* the new offsets. This parameter controls the number of entries added to
the
* entrylog before a flush is forced. A higher value for this parameter
means
* more memory will be used for offsets. Each offset consists of 3 longs.
*
* This parameter should _not_ be modified unless you know what you're
doing.
* The default is 100,000.
*
* @param maxOutstandingRequests number of entries to compact before
flushing
*
* @return ServerConfiguration
*/
public ServerConfiguration setCompactionMaxOutstandingRequests(int
maxOutstandingRequests) {
setProperty(COMPACTION_MAX_OUTSTANDING_REQUESTS,
maxOutstandingRequests);
return this;
}
------------------------
Thanks a lot.
-Jia
