about insert benchmark
Hi all, I run a benchmark with my own code and found that the 10 inserts performance is better than others, Why? Can anyone explain it? Thanks. Partitioner = OPP CL = ONE == 1000 records insert one:201 ms insert per:0.201 ms insert thput:4975.1245 ops/sec == 1 records insert one:1950 ms insert per:0.195 ms insert thput:5128.205 ops/sec == 10 records insert one:15576 ms insert per:0.15576 ms insert thput:6420.134 ops/sec == 50 records insert one:82177 ms insert per:0.164354 ms insert thput:6084.4272 ops/sec Shen
Re: about insert benchmark
Sorry, my Cassandra version is 0.6.4.
test
test
Can I retrieve specific key range from a table in RandomPartitioner?
Hi all, Can I retrieve specific key range from a table in RandomPartitioner? Because I always got below exception: Exception in thread main InvalidRequestException(why:start key's md5 sorts after end key's md5. this is not allowed; you probably should not specify end key at all, under RandomPartitioner) Thanks. Shen
Re: Can I retrieve specific key range from a table in RandomPartitioner?
I have a key range that between 00 and 001000, and my code as below: SlicePredicate predicate = new SlicePredicate(); predicate.setColumn_names(columns); ColumnParent parent = new ColumnParent(columnFamily); KeyRange k = new KeyRange(1000); k.setStart_key(key[0]); k.setEnd_key(key[1000]); ListKeySlice results = client.get_range_slices(keyspace, parent, predicate, k, ConsistencyLevel.ONE); On Thu, Aug 12, 2010 at 4:44 PM, ChingShen chingshenc...@gmail.com wrote: Hi all, Can I retrieve specific key range from a table in RandomPartitioner? Because I always got below exception: Exception in thread main InvalidRequestException(why:start key's md5 sorts after end key's md5. this is not allowed; you probably should not specify end key at all, under RandomPartitioner) Thanks. Shen
Re: Unreliable transport layer
Why? What reasons did you choose TCP? Shen On Sat, Mar 6, 2010 at 9:15 AM, Jonathan Ellis jbel...@gmail.com wrote: In 0.6 gossip is over TCP. On Fri, Mar 5, 2010 at 6:54 PM, Ashwin Jayaprakash ashwin.jayaprak...@gmail.com wrote: Hey guys! I have a simple question. I'm a casual observer, not a real Cassandra user yet. So, excuse my ignorance. I see that the Gossip feature uses UDP. I was curious to know if you guys faced issues with unreliable transports in your production clusters? Like faulty switches, dropped packets etc during heavy network loads? If I'm not mistaken are all client reads/writes doing point-to-point over TCP? Thanks, Ashwin.
Re: How to get the 'system' keyspace info?
Thanks Jonathan Ellis, I got an error message as below: ERROR [pool-1-thread-1] 2010-07-21 08:51:46,582 Cassandra.java (line 1242) Internal error processing get_slice java.lang.RuntimeException:* No replica strategy configured for system* Because the system keyspace is for Cassandra internals, so does it mean I can't get the system keyspace info? Thanks. Shen
How to get the 'system' keyspace info?
cassandra get system.LocationInfo['L'] Exception Internal error processing get_slice What's wrong? Thanks. Shen
Question about CL.ZERO
Hi all, Does it mean that the coordinator node always return success to the client at CL.ZERO? But if the coordinator node sends a request to a given node B(RF=1), then B is down, what happened? The coordinator node will write the hint locally? Thanks. Shen
Re: UnavailableException on QUORUM write
Which client library do you use? Shen On Fri, Jul 9, 2010 at 4:53 PM, Per Olesen p...@trifork.com wrote: Hi, I am a bit confused about getting an UnavailableException when doing a QUORUM write. I have a 3 node cluster, with RF=3. When all 3 nodes are up, the QUORUM write succeeds. When 1 of the 3 nodes are down, the QUORUM write fails with UnavailableException. Shouldn't it be enough with 2 nodes up for RF=3? Won't N/2+1 be 2 in my case? /Per
How to add a new Keyspace?
Hi all, If I want to add a new Keyspace, does it mean I have to distribute my storage-conf.xml to whole nodes? and restart whole nodes? Shen
Question about hinted handoff
Hi all, Please consider this case: (RF=1, CL=ONE) 1. I have A, B and C nodes. 2. A node is a coordinator node, it sends a request to B node to do write operation. 3. B node is down during write operation, so return failure message to client, and write a hint to C node. 4. B node comes back up, then C node forwards the data to it. 5. B node own data right now, although the write operation is failure. Correctly? Thanks. Shen
Gossip round time
Hi, I found the http://www.slideshare.net/adorepump/cassandra-nosql ppt, that mentioned State disseminated in* O(logN)* rounds where N is the number of nodes in the cluster. about gossip on page 11. Is it wrong to draw on page 15? does it need round 4? Thanks. Shen
Re: Question about hinted handoff
So, am I correctly? Shen On Thu, Jul 8, 2010 at 5:33 PM, Anty anty@gmail.com wrote: Sorry I am wrong .Miss the CF=one. On Thu, Jul 8, 2010 at 5:27 PM, Anty anty@gmail.com wrote: On Thu, Jul 8, 2010 at 4:11 PM, ChingShen chingshenc...@gmail.comwrote: Hi all, Please consider this case: (RF=1, CL=ONE) 1. I have A, B and C nodes. 2. A node is a coordinator node, it sends a request to B node to do write operation. No ,will not choose B , write the data locally in Node A. if RF=2 may choose C as hint and replica node. 3. B node is down during write operation, so return failure message to client, and write a hint to C node. 4. B node comes back up, then C node forwards the data to it. 5. B node own data right now, although the write operation is failure. Correctly? Thanks. Shen -- Best Regards Anty Rao -- Best Regards Anty Rao
Re: Question about hinted handoff
If so, when does hinted handoff work? On Thu, Jul 8, 2010 at 9:55 PM, Anty anty@gmail.com wrote: On Thu, Jul 8, 2010 at 4:11 PM, ChingShen chingshenc...@gmail.com wrote: Hi all, Please consider this case: (RF=1, CL=ONE) 1. I have A, B and C nodes. 2. A node is a coordinator node, it sends a request to B node to do write operation. 3. B node is down during write operation, so return failure message to client, and write a hint to C node. I think node A will return failure message to client. and will not write a hint to C node. 4. B node comes back up, then C node forwards the data to it. 5. B node own data right now, although the write operation is failure. Correctly? Thanks. Shen -- Best Regards Anty Rao
Re: Some questions about the write operation and hinted handoff
Thanks Jonathan Ellis, I want to make sure that after A return failure message to client at CL.ONE, *does A write a hint to C?* If so, although the write operation is failed, but the data is still stored in C? if B comes back up, then C forwards to B? Shen On Thu, Jul 8, 2010 at 10:08 PM, Jonathan Ellis jbel...@gmail.com wrote: On Thu, Jul 8, 2010 at 12:45 AM, ChingShen chingshenc...@gmail.com wrote: hmm... I'm really confused. The http://wiki.apache.org/cassandra/API document mentioned that if write ConsistencyLevel=ANY that Ensure the write has been written to at least 1 node, including hinted recipients., I couldn't imagine this case. :( If I have A,B,C and D nodes(RF=1), and write ConsistencyLevel=ANY, so A coordinator node sends a write request to another node(e.g. B node), but B node is down during write operation, what happend? return failure message to client immediately? or write a hint to another node(e.g. C node) It will write a hint and report success. But if you were writing at CL.ONE it would fail the write because a hinted write isn't readable until it can be forwarded to the right node (here, B). -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
Why is cassandra named cassandra?
Hi, Why is cassandra named cassandra? Thanks. Shen
Re: Some questions about the write operation and hinted handoff
On Fri, Jul 9, 2010 at 4:32 AM, Jonathan Ellis jbel...@gmail.com wrote: If the coordinator knows it can't achieve the requested CL it won't do any writes, hinted or otherwise, and will immediately report UnavailableException to the client. To summarize: hinted writes are only generated when Cassandra (a) knows a target is down ahead of time and (b) still has enough UP targets to satisfy the requested CL. Ok, If so, I suppose that A sends requests to B, C and D nodes(RF=3) at * CL.QUORUM*, but D is down, then return success message to the client, and* A write a hint to E node*? until D comes back up then E forwards the data to D? Thanks. Shen
Re: Which node is coordinator node?
Thanks aaron morton, I have an another question about replication. if I run a write operation on A node and how does the replication work? A node dispatches three request to B, C and D nodes respectively to do write operation? or A node dispatches a request to B node, then B node forwards it to C node, finally, C node forwards it to D node? Thanks. Shen On Tue, Jul 6, 2010 at 8:04 PM, aaron morton aa...@thelastpickle.comwrote: Which ever node the client connects to is the coordinator node. It will take care of sending the messages to the nodes who will do the actual work. If you have multiple nodes try a DNS round robin to distribute client connections around. Aaron On 6 Jul 2010, at 22:10, ChingShen wrote: Hi all, I'm newbie in Cassandra, I have a question about which node is coordinator node in my cluster. I have A, B, C, D, E, F and G nodes. if I run a write operation on A node, and key range between A and B, so the A node is responsible to write the key to B, C and D nodes(RF=3) ? and does it mean A node is coordinator node? Thanks. Shen
System control messages rely on UDP?
Hi all, I found the Cassandra paper(in 5.7 section) that mentioned all system control messages rely on UDP, but when I start up my cluster, I haven't see any informations about UDP. Why? TCP connections: port 7000 = Gossip port 9160 = Thrift service port 8080 = JMX Right? Shen
Re: Some questions about the write operation and hinted handoff
So, does it mean that only the CL=ZERO and CL=ANY support hinted handoff, right? Thanks. Shen On Wed, Jul 7, 2010 at 11:28 PM, Jonathan Ellis jbel...@gmail.com wrote: does http://wiki.apache.org/cassandra/HintedHandoff help? On Wed, Jul 7, 2010 at 10:16 AM, ChingShen chingshenc...@gmail.com wrote: Thanks Jonathan Ellis, If so, how does the hinted handoff work? I thought the coordinator node will write the data to another node(e.g. G node), I'm confused. Shen Second, if B node is down during the write operation, does it return failure(CL=ALL) to user? yes -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
Re: Some questions about the write operation and hinted handoff
hmm... I'm really confused. The http://wiki.apache.org/cassandra/API document mentioned that if write ConsistencyLevel=ANY that Ensure the write has been written to at least 1 node, including hinted recipients., I couldn't imagine this case. :( If I have A,B,C and D nodes(RF=1), and write ConsistencyLevel=ANY, so A coordinator node sends a write request to another node(e.g. B node), but B node is down during write operation, what happend? return failure message to client immediately? or write a hint to another node(e.g. C node) and return success message to client? or could anyone can give me a real case? Thanks. Shen On Thu, Jul 8, 2010 at 12:48 PM, Jonathan Ellis jbel...@gmail.com wrote: No, it means that HH writes don't count towards meeting the requested ConsistencyLevel. On Wed, Jul 7, 2010 at 9:36 PM, ChingShen chingshenc...@gmail.com wrote: So, does it mean that only the CL=ZERO and CL=ANY support hinted handoff, right? Thanks. Shen On Wed, Jul 7, 2010 at 11:28 PM, Jonathan Ellis jbel...@gmail.com wrote: does http://wiki.apache.org/cassandra/HintedHandoff help? On Wed, Jul 7, 2010 at 10:16 AM, ChingShen chingshenc...@gmail.com wrote: Thanks Jonathan Ellis, If so, how does the hinted handoff work? I thought the coordinator node will write the data to another node(e.g. G node), I'm confused. Shen Second, if B node is down during the write operation, does it return failure(CL=ALL) to user? yes -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
Which node is coordinator node?
Hi all, I'm newbie in Cassandra, I have a question about which node is coordinator node in my cluster. I have A, B, C, D, E, F and G nodes. if I run a write operation on A node, and key range between A and B, so the A node is responsible to write the key to B, C and D nodes(RF=3) ? and does it mean A node is coordinator node? Thanks. Shen
Some questions about the write operation and hinted handoff
Hi all, I have A, B, C, D, E, F and G nodes(RF=3), if I run a write operation(CL=ALL) on A node(coordinator), and the key range between A and B, therefore, the data will be stored on B, C and D nodes, right? Second, if B node is down during the write operation, does it return failure(CL=ALL) to user? or write the data to the another node(e.g. G node) until B comes back up and G forwards the data to him? Thanks. Shen
