莱布尼兹

花了二天时间看了下相关资料，当然也做了些demo,感觉挺好。 hbase 是基于hdfs的，分布式的面向列储存的数据储存系统。正是这些特点，使得它是很好应用于实时读写，随时访问超大数据集的情景。在结构上，有点类似于hdfs设计，同样由hbase master,hregion sever(slaves).组成，其中hregion储存基于个region(相当于table)。在建立regio...

   serial nosolutionslevelpreconditinorunonflowadvancesshortcomingsuse cases1direct client APIlog-  transfer datavia bothclusters  ...

how many regions are thinked as too few or to too many? some conditions are worth of consideration for a table(regardless of hbase's configurations):-first ,keep the cluster more 'static' when u...

below views are all from hbase's guide(maybe with my some comments fonted by deferent size) Overall, HBase implements close to all of the features described in Chapter 1. Where it differs,...

1in case of ONE region,a table with 10 rows and two familys(each contains 10 cols),if a Scan is set by caching and batch below will spawn appitiate rpcs:  in generate ,a additional rpc is generate...

we have a cluster about 25 nodes,which are installed hbase-0.94.2,yeah it is find for over second weeks.but last two weeks i upgaded to 0.94.16,there are some bad network showed in ganglia.as below:...

 1.what is snappy   2.why to use it  3.how it to work  4.compare to similar compressions  5.install it on hadoop  6.intall it on hbase  6.2 verifya.b.c....

i worked to benchmark hbase performance this weekend as i never used to do this befoer.after completion of these tasks,i found some good test methods and implied interesting.   some conclusion...

why  along with the time goes,as unreasonable table design,or some crash nodes etc,these will cause some regionservers have overloaded regions and/or much underloaded regions,so a balancer is nece...

Introducing Hoya – HBase on YARN application architecutre 

    IF u want to compile a hbase project specified to your own hardware configures(eg. 32 bit jdk to 64),OR release after some changes eg. applied a patch ,optimized some features,u can try this o...

   as u know,the hbas's data logs (akka wal) will roll after certain intervals to speedup restore data lost occasionally.and of course,both log rolling and flush memstore will block up all wirtes ...

 there is no notable performance increments in case of using 'get' query and with high hit ratio.(as hbase internally supports range hash already).but there is a try worth if multi storefiles exist ...

  u know,when u shutdowning a hbase cluster,sometimes it costs very long time to complete.and now how to fiind what regionservers are kept on alive is simple and directly by following these steps: ...

 1.the match relationships between hadoop and hbase nowaday   that means if you are now using hadoop1.0.x and hbase-0.94.x,and assume u want to upgrade to hadoop-2.5.x and hbase-1.0.x,the step...

  i wanna export a table to json format files,but after gging,nothing solutions found.i known,pig is used to do soome sql like mapreduces stuff; and hive is a dataware to build on hbase.but i cant s...

The following gives you a list to run through when you encounter problems with your cluster setup.1.Basic setup checklist This section provides a checklist of things you should confirm for...

  * table disabled is NOT different from region,when all regions have been closed,then the table 's disabled finally.* region closing state is set on zk from client,and transition to closed by...

在看wiki时有这样的字样：HBase: Bigtable-like structured storage for Hadoop HDFS觉得不对劲，明明是说是面向列族儲存的（希疏的数据），怎么又说成是结构化儲存呢？今天在别人blog得到确认。Hadoop Hbase适合存储哪类数据？(转)今天在看中科院家伙的文章说是：半结构化或非结构化数据的结构化存储（see csd...

refer to 0.20.6 version yes ,as hbase will use Local fs to access so it's needless to start hadoop (which is run in any mode).do it like this simplely:   start-hbase.sh check success o...

refer to 0.20.6 versionthis is a little different from standalone install ,as hbase will use pesudo/real cluster hadoop .so some diferences are listed below:A.hbase-site.xml1)hbase.rootdiru ...

refer to 0.20.6 version＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝1 －－－－－ use hbase's built in-zookeeper instance  as coordinator     2－－－－－ use zookeeper cluster as coordinatorwithin this intall...

hbase's architecture overview:note:* why hbase use zookeeper but hadoop?hbase use zk to implements the heartbeat mechanism ,and hadoop use build-in heartbeat to detect node states ...

经过几天来的看资料，写代码，终于对这个东东有点眉目了。package linhon.crud;import java.util.Date;import java.util.Map.Entry;import java.util.NavigableMap;import org.apache.hadoop.hbase.HBaseConfiguration;import o...

 today i will learn to hit the hbase source codes.for  the rule from simple to difficult,i will get a standalone mode to run hbase to do this.ok,let's look at the shell  start-hbase.sh i...

hbase本身已经提供了实时查询功能了,如bloom filters等.如果加入mr的话,那么好处是什么呢? 如果使用mr对hbase中的数据进行非实时性的统计分析,这是可行的,但这样已经有了替代方案:hive.这正如pig基于hadoop一样,将mr的业务抽取出来了. references:http://hadoop.nchc.org.tw/phpbb/viewtopic...

there are some steps to add a new node to hbase mentioned below: prerequest  sync time    env   /etc/hostsssh-copy-id  let master login to new node without password start new n...

1.principle    2.note-as is hbase-0.94.2,the table .meta. is not splittable,therefore,there is only ONE region in table -root-.that is if you try to split the root you will do it w/o err...

flow:    FAQ:-why META table can not be splited?if u try to split the table 'meta',u will see the warn log :  Cannot split meta regions in HBase 0.20 and abovei dont know how this case a...

flow:   some conclusions:--there is  a mutation process mudel interacts Memstore with HLog,  1.MVCC insert 'memStoreWriter' number,then write back these edits to Memstore(s) with this numb...

todo,todo........

 read    Note:-Gets will be converted to scan per Get in RS-scan is needless to use offset for retrieving ranged rows.this is different from common RMDBS.and this is implemented by RS ...

   just recovered from a disease,i should finish the retain part of work now...  yes,as u can see,the Scan/Get oper from hbase is some more tricky,as the kvs multi-dimensions and related to stor...

env:hbase,94.26zookeeper,3.4.3---------------1.downed node  this morning we found a regionserver(host-34) downed in our monitor.so we dived into the logs of hbase and found that in this ho...