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I am getting multiple warnings about:

WARN : Max open files on localhost is 1024, recommend 32768

I am unsure what this is about.

/usr/local/accumulo$ ./bin/start-all.sh &
[1] 27142
/usr/local/accumulo$ Starting monitor on localhost
WARN : Max open files on localhost is 1024, recommend 32768
Starting tablet servers .... done
Starting tserver on localhost
WARN : Max open files on localhost is 1024, recommend 32768
2016-12-01 15:14:49,820 [fs.VolumeManagerImpl] WARN : dfs.datanode.synconclose set to false in hdfs-site.xml: data loss is possible on   hard system reset or power loss
2016-12-01 15:14:49,838 [server.Accumulo] INFO : Attempting to talk to zookeeper
2016-12-01 15:14:50,017 [server.Accumulo] INFO : ZooKeeper connected and initialized, attempting to talk to HDFS
2016-12-01 15:14:50,184 [server.Accumulo] INFO : Connected to HDFS
Starting master on localhost
WARN : Max open files on localhost is 1024, recommend 32768
Starting gc on localhost
WARN : Max open files on localhost is 1024, recommend 32768
Starting tracer on localhost
WARN : Max open files on localhost is 1024, recommend 32768

I am getting another warning that I understand. But the one about max open files is strange to me.

How do I resolve these warnings?

By the way, Accumulo is running.

Here are more details about my setup:

No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04.1 LTS Release: 16.04 Codename: xenial

8GB of RAM. Only 2.3GB is being used (with Accumulo).

jnbdz
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1 Answers1

4

It is the number of maximum of open file descriptors at a time. You can increase it by running:

ulimit -n 32768
hgminh
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    Beware that this will not persist a restart of the machine. Be sure to set this via /etc/security/limits.conf or a file in /etc/security/limit.d/ – elserj Dec 01 '16 at 21:05
  • It would be really nice if the error message contained this answer. – Mark Feb 12 '18 at 14:21