Is there any work being done in that I could have my puts write to 3 nodes in-memory(which asynchronously write to the WAL)? Is that a possibility? Then if 1 or 2 nodes go down, I can still recover. Obviously if all 3 go down, I would have a problem.
Thanks, Dean -----Original Message----- From: tsuna [mailto:[email protected]] Sent: Thursday, February 24, 2011 10:05 AM To: [email protected] Cc: Hiller, Dean (Contractor) Subject: Re: when does put return to the caller? On Wed, Feb 23, 2011 at 1:25 PM, Hiller, Dean (Contractor) <[email protected]> wrote: > I was wonder if put returns after writing the data into memory on two > out of the three nodes letting my client continue so we don't have to > wait for the memory to then go to disk. After all, if it is replicated, > probably don't need to wait for it to be written to disk(ie. Kind of > like the in-memory data grids that exist out there). If you use the WAL (Write Ahead Log), which is enabled by default, your write has to be persisted on 3 disks before it returns successfully to you. Without the WAL, the write is only written to memory of one node, so if that node crashes, you'll lose your edit (much faster but unsafe). > Also, is there an asynchronous request/response for PutAll so I can slam > the grid with batches of 1000 entries kind of like > > PutAll(List<PutOps> puts, AsynchCallback cb); such that cb would be > called with the failure or success response after the put? HBase doesn't offer any asynchronous API out of the box, and in addition HTable isn't thread-safe. If you want an asynchronous HBase API, I recommend you take a look at asynchbase (https://github.com/stumbleupon/asynchbase) as it's an alternative HBase client that is entirely asynchronous and non-blocking. Javadoc is at http://su.pr/1PJCSY -- Benoit "tsuna" Sigoure Software Engineer @ www.StumbleUpon.com This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.
