> My question is how is this HLog file different from a StoreFile? Why is it > faster to write to an HLog file and not write directly to a StoreFile?
Read this: http://www.larsgeorge.com/2010/01/hbase-architecture-101-write-ahead-log.html and http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html --Suraj On Fri, Jul 13, 2012 at 3:42 AM, Sever Fundatureanu <fundatureanu.se...@gmail.com> wrote: > Hello, > > I would like to understand more in-depth how fault tolerance is handled in > HBase: > > 1. So for each put operation an RS first writes to an HLog file and then to > the Memstore. If the RS crashes the HLog file is replayed by other servers, > correct? > My question is how is this HLog file different from a StoreFile? Why is it > faster to write to an HLog file and not write directly to a StoreFile? > > 2. How is fault tolerance handled for an RS with a coprocessor loaded? Will > other servers load that coprocessor if the original RS crashes? If yes, > will the HLog be replayed with the coprocessor already loaded? > > Thanks in advance for the responses. > -- > Sever Fundatureanu > > Vrije Universiteit Amsterdam > E-mail: fundatureanu.se...@gmail.com
