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


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Re: HBase read perfomnance and HBase client
lars hofhansl 2013-08-01, 06:15
Yeah, that would seem to indicate that seeking into the block is not a bottleneck (and you said earlier that everything fits into the blockcache).
Need to profile to know more. If you have time, would be cool if you can start jvisualvm and attach it to the RS start the profiling and let the workload run for a bit.

-- Lars

----- Original Message -----
From: Vladimir Rodionov <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]; lars hofhansl <[EMAIL PROTECTED]>
Cc:
Sent: Wednesday, July 31, 2013 9:57 PM
Subject: Re: HBase read perfomnance and HBase client

Smaller block size (32K) does not give any performance gain and this is
strange, to say the least.
On Wed, Jul 31, 2013 at 9:33 PM, lars hofhansl <[EMAIL PROTECTED]> wrote:

> Would be interesting to profile MultiGet. With RTT of 0.1ms, the internal
> RS friction is probably the main contributor.
> In fact MultiGet just loops over the set at the RS and calls single gets
> on the various regions.
>
> Each Get needs to reseek into the block (even when it is cached, since KVs
> have variable size).
>
> There are HBASE-6136 and HBASE-8362.
>
>
> -- Lars
>
> ________________________________
> From: Vladimir Rodionov <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED]; lars hofhansl <[EMAIL PROTECTED]>
> Sent: Wednesday, July 31, 2013 7:27 PM
> Subject: Re: HBase read perfomnance and HBase client
>
>
> Some final numbers :
>
> Test config:
>
> HBase 0.94.6
> blockcache=true, block size = 64K, KV size = 62 bytes (raw).
>
> 5 Clients: 96GB, 16(32) CPUs (2.2Ghz), CentOS 5.7
> 1 RS Server: the same config.
>
> Local network with ping between hosts: 0.1 ms
>
>
> 1. HBase client hits the wall at ~ 50K per sec regardless of # of CPU,
> threads, IO pool size and other settings.
> 2. HBase server was able to sustain 170K per sec (with 64K block size). All
> from block cache. KV size = 62 bytes (very small). This is for single Get
> op, 60 threads per client, 5 clients (on different hosts)
> 3. Multi - get hits the wall at the same 170K-200K per sec. Batch size
> tested: 30, 100. The same performance absolutely as with batch size = 1.
> Multi get has some internal issues on RegionServer side. May be excessive
> locking or some thing else.
>
>
>
>
>
> On Tue, Jul 30, 2013 at 2:01 PM, Vladimir Rodionov
> <[EMAIL PROTECTED]>wrote:
>
> > 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 <