Re: [In Memory] Questions about Make HBase Table In Memory

Thanks Ted for your reply, the idea actually based on the HBase doc about Block Cache Design, so with IN_MEMORY=true and proactively read(GET/SCAN) the table, we can get the table served from memory for best and stable read performance. On 24 October 2016 at 11:19, Ted Yu

Re: [In Memory] Questions about Make HBase Table In Memory

Puts are stored in memstore. Get / Scan would include such data in memstore when row keys match. For #2, see http://hbase.apache.org/book.html#block.cache.design For #3, one indication is latency of the result. Latency would be longer when disk is involved. On Sun, Oct 23, 2016 at 8:01 PM,

Re: Hbase Row key lock

As per my experience, in normal case lock wont be held for 60 seconds. How many writes/sec per node you are doing? Seems like there is some hotspotting in your use case or cluster might need some tuning/tweaking. Have you verified that your writes/reads are evenly spread out. Do u have a time

Re: Hbase Row key lock

Manjeet: Did you have a chance to get jstack during the lock contention period ? Cheers > On Oct 23, 2016, at 12:57 PM, Manjeet Singh > wrote: > > Anil all information are correct I am talking about suppose I didn't set > any version and I have very simple

Re: Hbase Row key lock

Writes/Updates usually takes few milliseconds in HBase. So, in normal cases lock wont be held for seconds. On Sun, Oct 23, 2016 at 12:57 PM, Manjeet Singh wrote: > Anil all information are correct I am talking about suppose I didn't set > any version and I have very

[ANNOUNCE] Apache HBase 1.1.7 is now available for download

Apache HBase 1.1.7 is now available for download. Get it from an Apache mirror [1] or Maven repository. The list of changes in this release can be found in the release notes [2] or at the bottom of this announcement. Thanks to all who contributed to this release. Best, The HBase Dev Team 1.

[ANNOUNCE] Apache HBase 0.98.23 is now available for download

Apache HBase 0.98.23 is now available for download. Get it from an Apache mirror [1] or Maven repository. The list of changes in this release can be found in the release notes [2] or at the bottom of this announcement. Thanks to all who contributed to this release. Best, The HBase Dev Team 1.

Re: Hbase Row key lock

Anil all information are correct I am talking about suppose I didn't set any version and I have very simple requirement to update if I found xyz record and if I hv few ETL process which are responsible for aggregate the data which is very common. ... why my hbase stuck if I try to update same

Re: Hbase Row key lock

Writes within a HBase row are atomic. Now, whichever write becomes the latest write(with the help of timestamp value) will prevail as the default value. If you set versions to more than 1 in column family, then you will be able to see both the values if you query for multiple versions. HTH, Anil

Re: Hbase Row key lock

Till now what i understand their is no update if two different thread try to update same record what happen first record insert with some version second thread comes and change the version and its like a new insert with some version this process called MVCC If I am correct how hbase support

Re: Hbase Row key lock

No I don't have 50 clients? I want to understand internal working of Hbase in my usecase I have bulk update operation from spark job we have 7 different kafka pipeline and 7 spark job it might happen that my 2 0r 3 spark job have same rowkey for update On Mon, Oct 24, 2016 at 12:20 AM, Dima

Re: Hbase Row key lock

If your typical use case sees 50 clients simultaneously trying to update the same row, then a strongly consistent data store that writes to disk for fault tolerance may not be for you. That said, such a use case seems extremely unusual to me and I'd ask why you're trying to update the same row in

Re: Hbase Row key lock

Hi Dima, I didn't get ? point is assume I have 50 different client all having same rowkey all want to update on same rowkey at same time now just tell what will happen? who will get what value? Thanks Manjeet On Mon, Oct 24, 2016 at 12:12 AM, Dima Spivak wrote: > Unless

Re: Hbase Row key lock

Unless told not to, HBase will always write to memory and append to the WAL on disk before returning and saying the write succeeded. That's by design and the same write pattern that companies like Apple and Facebook have found works for them at scale. So what's there to solve? On Sunday, October

Re: Hbase Row key lock

Hi All, I have read below mention blog and it also said Hbase holds the lock on rowkey level https://blogs.apache.org/hbase/entry/apache_hbase_internals_locking_and (0) Obtain Row Lock (1) Write to Write-Ahead-Log (WAL) (2) Update MemStore: write each cell to the memstore (3) Release Row Lock