Replication policy in HDFS is pluggable, since hadoop 0.21: https://issues.apache.org/jira/browse/HDFS-385
- Milind On 10/10/11 10:26 PM, "Uma Maheswara Rao G 72686" <mahesw...@huawei.com> wrote: >To get the best performance from Hadoop, we can configure network >topology. >Based on that, it will apply RackAwareness algorithms and write/read the >files. > Also HDFS-2246 will improve performance by reading directly local >replicas. > >If you have good algorithm and will get good performance than this >current algorithms, please file a JIRA with your proposed strategy and >design doc. :-) > >Thanks & Regards, >Uma > >----- Original Message ----- >From: gschen <gongsuoc...@yahoo.com.cn> >Date: Tuesday, October 11, 2011 9:26 am >Subject: Re: Strategy Of Replica >To: common-dev@hadoop.apache.org > >> On 2011/10/11 11:13, Uma Maheswara Rao G 72686 wrote: >> > I did not get your proposed strategy implementations. >> > >> > Note that, already you can set the replication levels for files. >> If you set less replication, then obviously your perf and space >> will get benefits and also risk will be high in this case. I think >> we can manage your requirements using that replication factor. >> Your expectations are something different that this? >> > >> > Regards, >> > Uma >> > ----- Original Message ----- >> > From: gschen<gongsuoc...@yahoo.com.cn> >> > Date: Tuesday, October 11, 2011 8:14 am >> > Subject: Strategy Of Replica >> > To: "common-dev@hadoop.apache.org"<common-dev@hadoop.apache.org> >> > >> >> Hi guys, >> >> What do you think of the strategy of replication in hdfs? How about >> >> the >> >> customized strategy that users customized their strategy of >> >> replication >> >> such as price, performance and so on? >> >> >> >> Thank you in advance. >> >> >> Thanks for your reply. In hdfs only one thing we can do is that we >> could >> set replication factor to change replication strategy, but we can >> not >> change where the block is stored and what type of storage that we >> stored >> the data. Just think this case: In order to improve the >> downloading >> speed, I can choose my block replication near my location or near >> someone's location. I mean that users could have more option to >> decide >> their block replication strategy. >> >
