Hello,
Is there a way to throttle the speed at which under-replicated blocks are
copied across a cluster? Either limiting the bandwidth or the number of
blocks per time period would work.
I'm currently running Hadoop v1.0.1. I think the
dfs.namenode.replication.work.multiplier.per.iteration opt
Since this is a Hadoop question, it should be sent
user@hadoop.apache.org (which I'm now sending this to and I put
user@hbase in BCC).
J-D
On Thu, Jan 17, 2013 at 9:54 AM, Brennon Church wrote:
> Hello,
>
> Is there a way to throttle the speed at which under-replicated blocks are
> copied across
You can limit the bandwidth in bytes/second values applied
via dfs.balance.bandwidthPerSec in each DN's hdfs-site.xml. Default is 1
MB/s (1048576).
Also, unsure if your version already has it, but it can be applied at
runtime too via the dfsadmin -setBalancerBandwidth command.
On Thu, Jan 17, 20
That doesn't seem to work for under-replicated blocks such as when
decommissioning (or losing) a node, just for the balancer. I've got
mine currently set to 10MB/s, but am seeing rates of 3-4 times that
after decommissioning a node while it works on bringing things back up
to the proper replic
Not true per the sources, it controls all DN->DN copy/move rates, although
the property name is misleading. Are you noticing a consistent rise in the
rate or is it spiky?
On Fri, Jan 18, 2013 at 2:20 AM, Brennon Church wrote:
> That doesn't seem to work for under-replicated blocks such as when
Pretty spiky. I'll throttle it back to 1MB/s and see if it reduces
things as expected.
Thanks!
--Brennon
On 1/17/13 1:41 PM, Harsh J wrote:
Not true per the sources, it controls all DN->DN copy/move rates,
although the property name is misleading. Are you noticing a
consistent rise in the r
One reason (for spikes) may be that the throttler actually runs
periodically (instead of controlling the rate at source, we detect and
block work if we exceed limits, at regular intervals). However, this period
is pretty short so it generally does not cause any ill effects on the
cluster.
On Fri,
