Re: Repair Strategies

Just a reminder, kindly provide your comments and suggestions. On Thu, Dec 5, 2019 at 3:46 PM Adarsh Kumar wrote: > Hi, > > We are in the process of designing a new solution around cassandra. As > repairs are very critical tasks for cassandra clusters want some pointers > on the following: > >

RE: Data is not syncing up when we add one more Node(DR) to existing 3 node cluster

Hi Raman, Thanks for the response. I will try and let you know the status. We have to do it on production environment, so might be it will take time to proceed. Regards, Anil Ganipineni P Please consider environment before printing this page. From: raman gugnani Sent: 12 December 2019 09:49

Re: execute is faster than execute_async?

Jon Haddad 於 2019年12月12日 週四 上午12:42寫道： > I'm not sure how you're measuring this - could you share your benchmarking > code? > >> s the details of theri? >> > start = time.time() for i in range(40960): prep = session.prepare(query, (args)) session.execute(prep) # or session.execute_async(p

Re: Data is not syncing up when we add one more Node(DR) to existing 3 node cluster

HI Anil, Please follow the below link. https://thelastpickle.com/blog/2019/02/26/data-center-switch.html Did you ran the command nodetool rebuild old_dc_name to stream the old historical data to new data center. Step 9 of the above article. On Thu, 12 Dec 2019 at 09:39, Anil Kumar Ganipineni

How to know execute_async correctly?

I tried to execute async by batch in python-driver. But I don't know how to check query executing correctly. Code is like below: B = BatchStatement() for x in xxx: B.add(query, (args)) res = session.execute_async(B) B.clear() # for reusing r = res.result() ## Then how to know my query works co

average row size in a cassandra table

How to find average row size of a table in cassandra? I am not looking for partition size (which can be found from nodetool tablehistograms), since a partition can have many rows. I am looking for row size.

Data is not syncing up when we add one more Node(DR) to existing 3 node cluster

Hi All, We have 3 node cluster on datacentre DC1 and below is our key space declaration. The current data size on the cluster is ~10GB. When we add a new node on datacentre DC2, the new node is not syncing up with the data, but it is showing UN when I run the nodetool status. CREATE KEYSPACE p

Re: Cassandra is not showing a node up hours after restart

Hello Paul, The behavior looks similar to what we experienced and reported. https://issues.apache.org/jira/browse/CASSANDRA-15138 In our testing, "service cassandra stop" makes a cluster sometimes in a wrong state. How about doing kill -9 ? Thanks, Hiro On Sun, Dec 8, 2019 at 7:47 PM Hossein Gh

Re: [EXTERNAL] Re: Connection Pooling in v4.x Java Driver

Hi Alexandre, Thank you for the explanation. I understand that reasoning very well now. Jon, appreciate the link, and will follow up there for this sort of thing then. Thanks, Kevin From: Alexandre Dutra Reply-To: "user@cassandra.apache.org" Date: Wednesday, December 11, 2019 at 3:33 AM To

Re: execute is faster than execute_async?

I'm not sure how you're measuring this - could you share your benchmarking code? I ask because execute calls execute_async under the hood: https://github.com/datastax/python-driver/blob/master/cassandra/cluster.py#L2316 I tested the python driver a ways back and found some weird behavior due to t

Re: execute is faster than execute_async?

Also note that you should be expecting async operations to be slower on a call-by-call basis. Async protocols have added overhead. The point of them really is to leave the client free to interleave other computing activity between the async calls. It’s not usually a better way to do batch wri

[ANNOUNCE] Gemini - an automated random test suite for Scylla and Apache Cassandra

Hi, We are happy to announce Gemini, an automated random testing suite for Scylla and Apache Cassandra clusters: https://github.com/scylladb/gemini We are using the tool internally to test Scylla, but there's nothing Scylla-specific about it. The tool is written in Go and uses the gocql driver t

Re: execute is faster than execute_async?

Hi, you can check this piece of documentation from Datastax: https://docs.datastax.com/en/developer/python-driver/3.20/api/cassandra/cluster/#cassandra.cluster.Session.execute_async The usual way of doing this is to send a bunch of execute_async() calls, adding the returned futures in a list. Onc

Re: Connection Pooling in v4.x Java Driver

Hi, In driver 4.x, pools do not resize dynamically anymore because the ratio between concrete benefits brought by this feature and the maintenance burden it caused was largely unfavorable: most bugs related to connection pooling in driver 3.x were caused by the dynamic pool resizing. Having a fixe

Re: execute is faster than execute_async?

I’m not very familiar with the python client unfortunately. If it helps: In Java, async would return futures and at the end of submitting each batch you would block on them by calling get. Jordan On Wed, Dec 11, 2019 at 1:37 AM lampahome wrote: > > > Jordan West 於 2019年12月11日 週三 下午4:34寫道： > >>

Re: execute is faster than execute_async?

Jordan West 於 2019年12月11日 週三 下午4:34寫道： > Hi, > > Have you tried batching calls to execute_async with periodic blocking for > the batch’s responses? > Can you give me some keywords about calling execute_async batch? PS: I use python version.

Re: execute is faster than execute_async?

Hi, Have you tried batching calls to execute_async with periodic blocking for the batch’s responses? I’ve witnessed this behavior as well with large or no batches and while I didn’t have time to investigate fully its likely due to message queuing behavior within Cassandra (pre-4.0). Smaller batche

execute is faster than execute_async?

I submit 1 row for 40960 times by session.execute() and session.execute_async() I found total time of execute() is always fast than execute_async Does that make sense? Or I miss the details of theri?