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https://issues.apache.org/jira/browse/HDFS-13234?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16390739#comment-16390739
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He Xiaoqiao commented on HDFS-13234:
------------------------------------
Thanks [~kihwal],[~elgoiri] for your comments.
{quote}How big is a single instance in your use case? Bloated conf in dfs
client is obviously a serious issue, but it can create bigger issues in
apps/jobs.{quote}
Actually this is yarn logs upload service, and the size of single
{{Configuration}} instance which located at NodeManager is about 120KB, but it
is bloated to 600MB over all {{Configuration}} instances since two factors:
a. HDFS Federation + HA with QJM and there are dozens of nameservices (~20),
and it create {{ConfiguredFailoverProxyProvider}} instance for each name
service at client, while num of {{Configuration}} instances will *2;
b. there are 150 single threads at most to execute upload yarn logs to HDFS;
so, in the extreme case, memory footprint of {{Configuration}} instances will
occupy ~20 * 2 * 150 * 120KB;
{quote}New conf objects are created to prevent unintended conf update
propagation. {quote}
it is true to prevent unintended conf update propagation, I think there are
other ways to avoid clone the whole conf for only two parameters of
{{ConfiguredFailoverProxyProvider}} and {{IPFailoverProxyProvider}} and waste
huge memory resource probably as you mentioned, is there some suggestions?
[~kihwal]
Thanks again.
> Remove renew configuration instance in ConfiguredFailoverProxyProvider and
> reduce memory footprint for client
> -------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-13234
> URL: https://issues.apache.org/jira/browse/HDFS-13234
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: fs, ha, hdfs-client
> Reporter: He Xiaoqiao
> Priority: Major
> Attachments: HDFS-13234.001.patch
>
>
> The memory footprint of #DFSClient is very considerable in some special
> scenario since there are many #Configuration instances and occupy much memory
> resource (In an extreme case, org.apache.hadoop.conf.Configuration occupies
> over 600MB we meet under HDFS Federation an HA with QJM and there are dozens
> of NameNodes). I think some new Configuration instance is not necessary. Such
> as #ConfiguredFailoverProxyProvider initialization.
> {code:java}
> public ConfiguredFailoverProxyProvider(Configuration conf, URI uri,
> Class<T> xface, HAProxyFactory<T> factory) {
> this.xface = xface;
> this.conf = new Configuration(conf);
> ......
> }
> {code}
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