[ http://issues.apache.org/jira/browse/HADOOP-803?page=comments#action_12460102 ] Hairong Kuang commented on HADOOP-803: --------------------------------------
A LinkedList entry contains a pointer to the previous entry and a pointer to the next entry. So it is more expensive entry-wise. One problem with ArrayList is that it creates an array of size 10 by default. But because most of time the set size is 3, we could set the intial array size to be 3. > Reducing memory consumption on Namenode : Part 1 > ------------------------------------------------ > > Key: HADOOP-803 > URL: http://issues.apache.org/jira/browse/HADOOP-803 > Project: Hadoop > Issue Type: Bug > Components: dfs > Reporter: Raghu Angadi > Assigned To: Raghu Angadi > Attachments: block-refs-2.patch, block-refs-3.patch, > block-refs-5.patch > > > There appears to be some places in Namenode that allow reducing memory > consumption without intrusive code or feature changes. This bug is an initial > attempt making those changes. Please include your thoughts as well. > One change I am planning to make : > Currently one copy of each block exists for each of the replicas and one copy > for blockMap. I think they are all supposed to be same. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
