Re: read repair with consistency one

Hi Ben Thanks a lot. From my analysis of the code it looks like you are right. When global read repair kicks in all live endpoints are queried for data, regardless of consistency level. Only EACH_QUORUM is treated differently. Cheers Grzegorz 2018-04-22 1:45 GMT+02:00 Ben Slater

Re: read repair with consistency one

I haven't checked the code to make sure this is still the case but last time I checked: - For any read, if an inconsistency between replicas is detected then this inconsistency will be repaired. This obviously wouldn’t apply with CL=ONE because you’re not reading multiple replicas to find

Re: read repair with consistency one

I haven't asked about "regular" repairs. I just wanted to know how read repair behaves in my configuration (or is it doing anything at all). 2018-04-21 14:04 GMT+02:00 Rahul Singh : > Read repairs are one anti-entropy measure. Continuous repairs is another. > If you

Re: read repair with consistency one

Read repairs are one anti-entropy measure. Continuous repairs is another. If you do repairs via Reaper or your own method it will resolve your discrepencies. On Apr 21, 2018, 3:16 AM -0400, Grzegorz Pietrusza , wrote: > Hi all > > I'm a bit confused with how read repair

Re: Read Repair

On Wed, Jul 8, 2015 at 2:07 PM, Saladi Naidu naidusp2...@yahoo.com wrote: Suppose I have a row of existing data with set of values for attributes I call this State1, and issue an update to some columns with Quorum consistency. If the write is succeeded in one node, Node1 and and failed on

RE: Read Repair

-0700 Subject: Re: Read Repair From: rc...@eventbrite.com To: user@cassandra.apache.org; naidusp2...@yahoo.com On Wed, Jul 8, 2015 at 2:07 PM, Saladi Naidu naidusp2...@yahoo.com wrote: Suppose I have a row of existing data with set of values for attributes I call this State1, and issue an update

RE: Read Repair in cassandra

The request would return with the latest data. The read request would fire against node 1 and node 3. The coordinator would get answers from both and would merge the answers and return the latest. Then read repair might run to update node 3. QUORUM does not take into consideration whether an

Re: read repair across DC and latency

On Wed, Nov 19, 2014 at 4:51 PM, Jimmy Lin y2klyf+w...@gmail.com wrote: # When you said send read digest request to the rest of the replica, do you mean all replica(s) in current and other DC? or just the one last replica in my current DC and one of the co-ordinate node in other DC? (our

Re: read repair across DC and latency

Tyler, thanks for the detail explanation. Still have few questions in my mind # When you said send read digest request to the rest of the replica, do you mean all replica(s) in current and other DC? or just the one last replica in my current DC and one of the co-ordinate node in other DC?

Re: read repair across DC and latency

On Sun, Nov 16, 2014 at 5:13 PM, Jimmy Lin y2klyf+w...@gmail.com wrote: I have read that read repair suppose to be running as background, but does the co-ordinator node need to wait for the response(along with other normal read tasks) before return the entire result back to the caller? For

Re: Read repair

, there is no quorum until failed rack comes back up. Hope this explains the scenario. From: Aaron Morton Sent: ‎10/‎28/‎2013 2:42 AM To: Cassandra User Subject: Re: Read repair As soon as it came back up, due to some human error, rack1 goes down. Now for some rows it is possible that Quorum cannot

Re: Read repair

Yes, it helps. Thanks --- Original Message --- From: Aaron Morton aa...@thelastpickle.com Sent: October 31, 2013 3:51 AM To: Cassandra User user@cassandra.apache.org Subject: Re: Read repair (assuming RF 3 and NTS is putting a replica in each rack) Rack1 goes down and some writes happen

RE: Read repair

hour and 30 mins, there is no quorum until failed rack comes back up. Hope this explains the scenario. From: Aaron Mortonmailto:aa...@thelastpickle.com Sent: ‎10/‎28/‎2013 2:42 AM To: Cassandra Usermailto:user@cassandra.apache.org Subject: Re: Read repair As soon

Re: Read repair

As soon as it came back up, due to some human error, rack1 goes down. Now for some rows it is possible that Quorum cannot be established. Not sure I follow here. if the first rack has come up I assume all nodes are available, if you then lose a different rack I assume you have 2/3 of the

Re: Read-repair working, repair not working?

Hi Aaron, Many thanks for your reply - answers below. Cheers, Brian What CL are you using for reads and writes? I would first build a test case to ensure correct operation when using strong consistency. i.e. QUOURM write and read. Because you are using RF 2 per DC I assume you are

Re: Read-repair working, repair not working?

CL.ONE : this is primarily for performance reasons … This makes reasoning about correct behaviour a little harder. If there is anyway you can run some tests with R + W N strong consistency I would encourage you to do so. You will then have a baseline of what works. (say I make 100 requests

Re: Read-repair working, repair not working?

I’d request data, nothing would be returned, I would then re-request the data and it would correctly be returned: What CL are you using for reads and writes? I see a number of dropped ‘MUTATION’ operations : just under 5% of the total ‘MutationStage’ count. Dropped mutations in a multi

Re: read-repair and deletes / forgotten deletes

the 10 days is actually configurable... look into gc_grace. Basically, you always need to run repair once per/gc_grace period. You won't see empty/deleted rows go away until they're compacted away. On Mon, Oct 1, 2012 at 6:32 PM, Hiller, Dean dean.hil...@nrel.gov wrote: I know there is a 10 day

Re: read-repair and deletes / forgotten deletes

Thanks, (actually new it was configurable) BUT what I don't get is why I have to run a repair. IF all nodes became consistent on the delete, it should not be possible to get a forgotten delete, correct. The forgotten delete will only occur if I have a node down and out for 10 days and it comes

Re: read-repair and deletes / forgotten deletes

Oh, and I have been reading Aaron Mortan's article here http://thelastpickle.com/2011/05/15/Deletes-and-Tombstones/ On 10/1/12 12:46 PM, Hiller, Dean dean.hil...@nrel.gov wrote: Thanks, (actually new it was configurable) BUT what I don't get is why I have to run a repair. IF all nodes became

Re: read-repair and deletes / forgotten deletes

inline... On Mon, Oct 1, 2012 at 7:46 PM, Hiller, Dean dean.hil...@nrel.gov wrote: Thanks, (actually new it was configurable) BUT what I don't get is why I have to run a repair. IF all nodes became consistent on the delete, it should not be possible to get a forgotten delete, correct. The

Re: read-repair?

Re: read-repair?

sorry to be dense, but which is it? do i get the old version or the new version? or is it indeterminate? On 02/02/2012 01:42, Peter Schuller wrote: i have RF=3, my row/column lives on 3 nodes right? if (for some reason, eg a timed-out write at quorum) node 1 has a 'new' version of the

Re: read-repair?

sorry to be dense, but which is it?  do i get the old version or the new version?  or is it indeterminate? Indeterminate, depending on which nodes happen to be participating in the read. Eventually you should get the new version, unless the node that took the new version permanently crashed

Re: read-repair?

i have RF=3, my row/column lives on 3 nodes right?  if (for some reason, eg a timed-out write at quorum) node 1 has a 'new' version of the row/column (eg clock = 10), but node 2 and 3 have 'old' versions (clock = 5), when i try to read my row/column at quorum, what do i get back? You either

Re: read-repair?

Peter Schuller peter.schul...@infidyne.com wrote: i have RF=3, my row/column lives on 3 nodes right?  if (for some reason, eg a timed-out write at quorum) node 1 has a 'new' version of the row/column (eg clock = 10), but node 2 and 3 have 'old' versions (clock = 5), when i try to read my

Re: read repair and column range queries

The digest is based on the results of the same query as applied on different replicas. See the following for more details: http://wiki.apache.org/cassandra/ReadRepair http://www.datastax.com/docs/1.0/dml/data_consistency On Wed, Nov 30, 2011 at 11:38 PM, Thorsten von Eicken t...@rightscale.com

RE: read repair across datacenters?

: Monday, December 27, 2010 6:59 PM To: user Subject: Re: read repair across datacenters? https://issues.apache.org/jira/browse/CASSANDRA-982 On Mon, Dec 27, 2010 at 5:55 PM, Shu Zhang szh...@mediosystems.com wrote: Brandon, for a read with quorum CL, a response is returned to the client after half