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HBase, mail # dev - HBase read perfomnance and HBase client


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Re: HBase read perfomnance and HBase client
Vladimir Rodionov 2013-07-30, 21:01
1. SCR are enabled
2. Single Configuration for all table did not work well, but I will try it
again
3. With Nagel I had 0.8ms avg, w/o - 0.4ms - I see the difference
On Tue, Jul 30, 2013 at 1:50 PM, lars hofhansl <[EMAIL PROTECTED]> wrote:

> With Nagle's you'd see something around 40ms. You are not saying 0.8ms RTT
> is bad, right? Are you seeing ~40ms latencies?
>
> This thread has gotten confusing.
>
> I would try these:
> * one Configuration for all tables. Or even use a single
> HConnection/Threadpool and use the HTable(byte[], HConnection,
> ExecutorService) constructor
> * disable Nagle's: set both ipc.server.tcpnodelay and
> hbase.ipc.client.tcpnodelay to true in hbase-site.xml (both client *and*
> server)
> * increase hbase.client.ipc.pool.size in client's hbase-site.xml
> * enable short circuit reads (details depend on exact version of Hadoop).
> Google will help :)
>
> -- Lars
>
>
> ----- Original Message -----
> From: Vladimir Rodionov <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED]
> Cc:
> Sent: Tuesday, July 30, 2013 1:30 PM
> Subject: Re: HBase read perfomnance and HBase client
>
> This hbase.ipc.client.tcpnodelay (default - false) explains poor single
> thread performance and high latency ( 0.8ms in local network)?
>
>
> On Tue, Jul 30, 2013 at 1:22 PM, Vladimir Rodionov
> <[EMAIL PROTECTED]>wrote:
>
> > One more observation: One Configuration instance per HTable gives 50%
> > boost as compared to single Configuration object for all HTable's - from
> > 20K to 30K
> >
> >
> > On Tue, Jul 30, 2013 at 1:17 PM, Vladimir Rodionov <
> [EMAIL PROTECTED]
> > > wrote:
> >
> >> This thread dump has been taken when client was sending 60 requests in
> >> parallel (at least, in theory). There are 50 server handler threads.
> >>
> >>
> >> On Tue, Jul 30, 2013 at 1:15 PM, Vladimir Rodionov <
> >> [EMAIL PROTECTED]> wrote:
> >>
> >>> Sure, here it is:
> >>>
> >>> http://pastebin.com/8TjyrKRT
> >>>
> >>> epoll is not only to read/write HDFS but to connect/listen to clients
> as
> >>> well?
> >>>
> >>>
> >>> On Tue, Jul 30, 2013 at 12:31 PM, Jean-Daniel Cryans <
> >>> [EMAIL PROTECTED]> wrote:
> >>>
> >>>> Can you show us what the thread dump looks like when the threads are
> >>>> BLOCKED? There aren't that many locks on the read path when reading
> >>>> out of the block cache, and epoll would only happen if you need to hit
> >>>> HDFS, which you're saying is not happening.
> >>>>
> >>>> J-D
> >>>>
> >>>> On Tue, Jul 30, 2013 at 12:16 PM, Vladimir Rodionov
> >>>> <[EMAIL PROTECTED]> wrote:
> >>>> > I am hitting data in a block cache, of course. The data set is very
> >>>> small
> >>>> > to fit comfortably into block cache and all request are directed to
> >>>> the
> >>>> > same Region to guarantee single RS testing.
> >>>> >
> >>>> > To Ted:
> >>>> >
> >>>> > Yes, its CDH 4.3 . What the difference between 94.10 and 94.6 with
> >>>> respect
> >>>> > to read performance?
> >>>> >
> >>>> >
> >>>> > On Tue, Jul 30, 2013 at 12:06 PM, Jean-Daniel Cryans <
> >>>> [EMAIL PROTECTED]>wrote:
> >>>> >
> >>>> >> That's a tough one.
> >>>> >>
> >>>> >> One thing that comes to mind is socket reuse. It used to come up
> more
> >>>> >> more often but this is an issue that people hit when doing loads of
> >>>> >> random reads. Try enabling tcp_tw_recycle but I'm not guaranteeing
> >>>> >> anything :)
> >>>> >>
> >>>> >> Also if you _just_ want to saturate something, be it CPU or
> network,
> >>>> >> wouldn't it be better to hit data only in the block cache? This way
> >>>> it
> >>>> >> has the lowest overhead?
> >>>> >>
> >>>> >> Last thing I wanted to mention is that yes, the client doesn't
> scale
> >>>> >> very well. I would suggest you give the asynchbase client a run.
> >>>> >>
> >>>> >> J-D
> >>>> >>
> >>>> >> On Tue, Jul 30, 2013 at 11:23 AM, Vladimir Rodionov
> >>>> >> <[EMAIL PROTECTED]> wrote:
> >>>> >> > I have been doing quite extensive testing of different read
> >>>> scenarios:
> >>>> >> >
> >>>> >