Set of SSTables have the same set of ancestors

Hello Cassandra-users, I logged into my test Cassandra cluster and saw this today. I find it very unusual that a set of SSTables have the same set of ancestors: $ sstablemetadata b800ks3-colla1-ka-*-Statistics.db | grep "Ancestors\|SSTable:" SSTable: ./b800ks3-colla1-ka-1876 Ancestors: [1840,

Re: Question on Read Repair

Yes: https://github.com/apache/cassandra/blob/81f6c784ce967fadb6ed7f58de1328e713eaf53c/src/java/org/apache/cassandra/db/ConsistencyLevel.java#L286 From: Anubhav Kale Reply-To: "user@cassandra.apache.org" Date: Tuesday, October

Re: Is there any way to throttle the memtable flushing throughput?

A few thoughts on the larger problem at hand. The AWS instance type you are using is not appropriate for a production workload. Also with memtable flushes that cause spiky write throughput it sounds like your commitlog is on the same disk as your data directory, combined with the use of non-SSD

Re: [Marketing Mail] Re: sstableloader question

How many sstables are you trying to load ? Running sstableloaders in parallel will help. Did you try setting the "-t" parameter and see if you are getting the expected throughput ? - Rajath Rajath Subramanyam On Mon, Oct 10, 2016 at 2:02 PM, Osman YOZGATLIOGLU <

RE: Question on Read Repair

Thank you. Interesting detail. Does it work the same way for other consistency levels as well ? From: Jeff Jirsa [mailto:jeff.ji...@crowdstrike.com] Sent: Tuesday, October 11, 2016 10:29 AM To: user@cassandra.apache.org Subject: Re: Question on Read Repair If the failuredetector knows that the

Re: Question on Read Repair

This is theory but not the all practice. The failure detector heartbeats is a process happening outside the read. Take for example a cluster with Replication Factor 3. At time('1) the failure detector might read three nodes as UP. A request "soon after '1" issued at time(`2) might start a read

Re: Question on Read Repair

If the failuredetector knows that the node is down, it won’t attempt a read, because the consistency level can’t be satisfied – none of the other replicas will be repaired. From: Anubhav Kale Reply-To: "user@cassandra.apache.org"

Question on Read Repair

Hello, This is more of a theory / concept question. I set CL=ALL and do a read. Say one replica was down, will the rest of the replicas get repaired as part of this ? (I am hoping the answer is yes). Thanks !

Is there any way to throttle the memtable flushing throughput?

Hi, I'm investigating the read/write performance of the C* (Ver. 2.2.8). However, I have an issue about memtable flushing which forces the spiky write throughput. And then it affects the latency of the client's requests. So I want to know the answers for the following questions. 1. Is there any

Does increment/decrement by 0 generate any commits ?

I just have a bunch of counters in 1 row, and I want to selectively update them. And I want to keep prepared queries. But I don't want to keep 30 prepared queries (1 for each counter column, but keep only 1). So in most cases, I will increment 1 column by positive integer and the others by 0.

Re: mapper.save() throws a ThreadPool error (Java)

Uh, yeah, I'm a moron. I was doing this inside a try/catch block, and the class containing my session was autoclosing the session at the end of the try/ catch (i.e try (Environment env = new Environment() ). Nvm, I'm an idiot On Tue, Oct 11, 2016 at 8:29 PM, Ali Akhtar

Re: mapper.save() throws a ThreadPool error (Java)

This is a little urgent, so any help would be greatly appreciated. On Tue, Oct 11, 2016 at 8:22 PM, Ali Akhtar wrote: > I'm creating a session, connecting to it, then creating a > mappingManager(), then obtaining a mapper for MyPojo.class > > If I then try to do

mapper.save() throws a ThreadPool error (Java)

I'm creating a session, connecting to it, then creating a mappingManager(), then obtaining a mapper for MyPojo.class If I then try to do mapper.save(myPojo), I get the following stacktrace: Oct 11, 2016 8:16:26 PM com.google.common.util.concurrent.ExecutionList executeListener SEVERE:

Re: Java Driver - Specifying parameters for an IN() query?

I'm not sure about using it in a SimpleStatement in the Java driver (you might need to test this), but the QueryBuilder does have support for in() where you pass a list is the parameter: see

Re: Java Driver - Specifying parameters for an IN() query?

You need to specify the values themselves. CREATE TABLE user ( id int, type text, val1 int, val2 text, PRIMARY KEY ((id, category), val1, val2) ); SELECT * FROM user WHERE id = 1 AND type IN ('user', 'admin') AND val1 = 3 AND val2 IN ('a', 'v', 'd'); On Tue, 11 Oct 2016 at 07:11 Ali Akhtar

Re: Java Driver - Specifying parameters for an IN() query?

Justin, I'm asking how to bind a parameter for IN queries thru the java driver. On Tue, Oct 11, 2016 at 7:22 PM, Justin Cameron wrote: > You need to specify the values themselves. > > CREATE TABLE user ( > id int, > type text, > val1 int, > val2 text, > PRIMARY KEY

Re: Java Driver - Specifying parameters for an IN() query?

Ah, thanks, good catch. If I send a List / Array as value for the last param, will that get bound as expected? On Tue, Oct 11, 2016 at 7:16 PM, horschi wrote: > Hi Ali, > > do you perhaps want "'Select * from my_table WHERE pk = ? And ck IN ?'" ? > (Without the brackets

Re: Java Driver - Specifying parameters for an IN() query?

Do you send the values themselves, or send them as an array / collection? Or will both work? On Tue, Oct 11, 2016 at 7:10 PM, Justin Cameron wrote: > You can pass multiple values to the IN clause, however they can only be > used on the last column in the partition key

Re: Java Driver - Specifying parameters for an IN() query?

Hi Ali, do you perhaps want "'Select * from my_table WHERE pk = ? And ck IN ?'" ? (Without the brackets around the question mark) regards, Ch On Tue, Oct 11, 2016 at 3:14 PM, Ali Akhtar wrote: > If I wanted to create an accessor, and have a method which does a query >

Re: Java Driver - Specifying parameters for an IN() query?

You can pass multiple values to the IN clause, however they can only be used on the last column in the partition key and/or the last column in the full primary key. Example: 'Select * from my_table WHERE pk = 'test' And ck IN (1, 2)' On Tue, 11 Oct 2016 at 06:15 Ali Akhtar

Java Driver - Specifying parameters for an IN() query?

If I wanted to create an accessor, and have a method which does a query like this: 'Select * from my_table WHERE pk = ? And ck IN (?)' And there were multiple options that could go inside the IN() query, how can I specify that? Will it e.g, let me pass in an array as the 2nd variable?