Are you lzo'ing Jack? If not, you probably should. St.Ack
On Wed, Sep 22, 2010 at 3:17 AM, Jack Levin <[email protected]> wrote: > So our cell sizes will be 350kb on average with 5-10 terabytes per server, I > just want to keep the count of Regions under 1000, per server > > -Jack > > > On Sep 22, 2010, at 2:44 AM, Ryan Rawson <[email protected]> wrote: > >> Region size is one of those tricky things, there are a few factors to >> consider: >> >> - regions are the basic element of availability and distribution. >> - HBase scales by having regions across many servers. Thus if you >> have 2 regions for 16GB data, on a 20 node machine you are a net loss >> there. >> - High region count has been known to make things slow, this is >> getting better, but it is probably better to have 700 regions than >> 3000 for the same amount of data. >> - Low region count prevents parallel scalability as per point #2. >> This really cant be stressed enough, since a common problem is loading >> 200MB data into HBase then wondering why your awesome 10 node cluster >> is mostly idle. >> - There is not much memory footprint difference between 1 region and >> 10 in terms of indexes, etc, held by the regionserver. >> >> Generally speaking I stick to the default, go smaller for hot tables, >> or manually split them, and go with a 1GB region size on our largest >> 900 GB table. >> >> -ryan >> >> On Wed, Sep 22, 2010 at 12:01 AM, Jack Levin <[email protected]> wrote: >>> Yes, I am thinking to put 10 to 15 million files on each regionserver >>> (well, not literally, but be controlled by regionserver). So thats >>> close to 4 TB worth of regions, which is about 4GB per region should >>> we target 1000 regions per server. Note, not all files are 'hot', and >>> I only expect to keep about 1% super hot, and 5% relatively hot, the >>> rest are cold. So in terms of keeping hbase blocks in RAM, that >>> should be adequate, for the rest we can afford a trip into hdfs. >>> >>> If servers are running 8 GB of ram, and are shared for regionservers >>> and datanodes, how much heap should I allocate to each? 6GB for RS >>> and 1GB for DN? >>> >>> Also, on the question whether 8 core x 16G Ram helps a Master server >>> to bring up the cluster faster, the answer is definitely - yes. It >>> took only 90 seconds to load 5000 regions across 13 servers, where >>> same task for Dual Core 8G Ram, took nearly 10 minutes. >>> >>> -Jack >>> >>> >>> >>> On Tue, Sep 21, 2010 at 11:38 PM, Stack <[email protected]> wrote: >>>> On Tue, Sep 21, 2010 at 11:11 PM, Jack Levin <[email protected]> wrote: >>>>> Its definitely binary, and I can even load it in my browser but >>>>> setting appropriate headers. So I guess for PUT and GET via Accept: >>>>> application/octet-stream there is no base64 encoding at all. >>>>> >>>> >>>> OK. Good. If it were base64'd, you'd see it. >>>> >>>>> Btw, out of curiosity I have region max file size set to 1GB now, but >>>>> what if I set it to say 10G or 50G? Is their significant overhead in >>>>> address seeking via HDFS? >>>>> >>>> >>>> You could do that. We don't have much experience running regions of >>>> that size. You should for sure pre-split your table on creation if >>>> you go this route (See HBaseAdmin API [1]). This method is not >>>> available in shell so you'd have to script it or write a little java >>>> to do it). >>>> >>>> St.Ack >>>> >>>> 1. >>>> http://hbase.apache.org/docs/r0.89.20100726/apidocs/org/apache/hadoop/hbase/client/HBaseAdmin.html#createTable(org.apache.hadoop.hbase.HTableDescriptor, >>>> byte[][]) >>>> >>> >
