Hey Lars!, I was on a similar line of investigation today, and I've filed https://issues.apache.org/jira/browse/HBASE-17760 to change the text. The pinning part of the text is relevant, but the command part isn't. In addition, you'd need to manually use the FavoredNodeLoadBalancer work to actually get HBase to apply pinning to its writes by passing around proper favored-node hint hostnames. I've also linked past and future relevant work JIRAs to that one.
Stumbled on this email when searching some follow-throughs, thought I'd drop a note. On Tue, 7 Mar 2017 at 20:18 Ted Yu <[email protected]> wrote: > bq. how that - apparently wrong - information came about > > Maybe Sean / Misty can give some context. > > Cheers > > On Tue, Mar 7, 2017 at 6:37 AM, Lars George <[email protected]> wrote: > > > Hey Ted, > > > > Thanks Cpt. Obvious :) > > > > I know how to use "blame" or git log how to find the JIRA, but what I was > > after is how that - apparently wrong - information came about. And if it > is > > wrong, what _is_ the current status of this feature. > > > > I do believe this is an important operational piece as it helps with > > rearranging clusters. Since it seems to still be missing, I am wondering > > what needs to be done here. > > > > Makes sense? > > > > Lars > > > > Sent from my iPhone > > > > > On 6 Mar 2017, at 19:50, Ted Yu <[email protected]> wrote: > > > > > > w.r.t. the first question, the quoted paragraph came from: > > > > > > HBASE-15332 Document how to take advantage of HDFS-6133 in HBase > > > > > >> On Mon, Mar 6, 2017 at 6:38 PM, Lars George <[email protected]> > > wrote: > > >> > > >> Hi, > > >> > > >> I am trying to grok what came out of all these issues about the HDFS > > >> balancer and being able to avoid it destroying HBase locality. There > > >> is this https://issues.apache.org/jira/browse/HBASE-13021 from JM, > and > > >> the book http://hbase.apache.org/book.html#_hbase_and_hdfs refers to > > >> https://issues.apache.org/jira/browse/HDFS-6133, stating: > > >> > > >> "HDFS-6133 provides the ability to exclude a given directory from the > > >> HDFS load balancer, by setting the dfs.datanode.block-pinning.enabled > > >> property to true in your HDFS configuration and running the following > > >> hdfs command: > > >> > > >> $ sudo -u hdfs hdfs balancer -exclude /hbase" > > >> > > >> I checked the Balancer class in 2.7.2 and it does not have that > > >> support, i.e. being able to exclude a path, it can only exclude hosts. > > >> That is also clear from HDFS-6133, which adds favoured nodes, but not > > >> being able to exclude paths (which would be nice). > > >> > > >> HBASE-13021 mentions that this works in tandem with the HBase favored > > >> node feature, but that makes it much more complicated since you have > > >> to pin individual regions to nodes, instead of doing that wholesale. > > >> > > >> Where does the above in the HBase book come from, and what is the > > >> current state as far as you know? > > >> > > >> Cheers, > > >> Lars > > >> > > >
