Hello all,
I am trying to export data from cassandra using CQL client. A column family
has about 10 rows in it. when i am copying dta into csv file using COPY
TO command i get following rpc_time out error.
copy mycolfamily to '/root/mycolfamily.csv'
Request did not complete within
Hi all!
We have a problem with cassandra 2.0. We have installed cassandra from
datastax community respository. We haven't changed any java options from
the default ones. De-facto Xmx is 1GB. Recently we have encountered a
couple of cases when cassandra stopped responding and the log was showing
Hi all!
We have experienced a strange issue with datastax opscenter. It showed much
more write requests that we should actually have. We've set everything up
on an isolated node and there without any activity it showed 100+ writes
per second. Is this some opscenter bug? Does it maybe count some
Anyone know how to debug cassandra processes just exiting? There is no info in
the cassandra logs and there is no heap dump file(which in the past has shown
up in /opt/cassandra/bin directory for me).
This occurs when running a map/reduce job that put severe load on the system.
The logs look
It is a little more involved than just changing the heap size. Every
cluster is different, so there isn't much of a set formula. Some areas to
look into, though:
**Caveat, we're still running in the 1.2 branch and 2.0 has some
differences in what is on versus off heap memory usage, but the
A random guess - possibly an OOM (Out of Memory) where Linux will kill a
process to recover memory when it is desperately low on memory. Have a look
in either your syslog output of the output of dmesg
cheers
On Wed, Sep 18, 2013 at 10:21 PM, Hiller, Dean dean.hil...@nrel.gov wrote:
Anyone
Check if java process got crashed. You can find hs_err*.log file in root
directory or cassandra working directory or temporary files directory.
Information in this log file can give an idea about failure.
On Wed, Sep 18, 2013 at 5:51 PM, Hiller, Dean dean.hil...@nrel.gov wrote:
Anyone know how
On 09/17/2013 04:44 PM, Robert Coli wrote:
On Thu, Sep 5, 2013 at 6:14 AM, Chris Burroughs
chris.burrou...@gmail.comwrote:
We have a 2 DC cluster running cassandra 1.2.9. They are in actual
physically separate DCs on opposite coasts of the US, not just logical
ones. The primary use of this
This shouldn't happen if you have swap active in the server
On Wednesday, September 18, 2013, Franc Carter wrote:
A random guess - possibly an OOM (Out of Memory) where Linux will kill a
process to recover memory when it is desperately low on memory. Have a look
in either your syslog output
On 09/17/2013 09:41 PM, Paulo Motta wrote:
So you're saying the only feasible way of enabling VNodes on an upgraded C*
1.2 is by doing fork writes to a brand new cluster + bulk load of sstables
from the old cluster? Or is it possible to succeed on shuffling, even if
that means waiting some weeks
Ah neat, I didn't know the dmesg command…that works great.
Dean
From: Franc Carter franc.car...@sirca.org.aumailto:franc.car...@sirca.org.au
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Wednesday, September
Swappiness is set to 60 though cassandra recommendations are to turn swap
completely off(we still have not done that as far as I know though) and sure
enough linux killed it.
Dean
From: Juan Manuel Formoso jform...@gmail.commailto:jform...@gmail.com
Reply-To:
We ran into this while tuning heap sizes. With Cassandra 1.2 making use of
off-heap memory, if we made our JVM too large relative to the server
memory, the system would just bail. We found for our app that the limit of
the JVM size relative to server memory was about 50%.
On Wed, Sep 18, 2013
Experts.. Any help?
On Wed, Sep 18, 2013 at 2:55 PM, pradeep kumar pradeepkuma...@gmail.comwrote:
Hello all,
I am trying to export data from cassandra using CQL client. A column
family has about 10 rows in it. when i am copying dta into csv file
using COPY TO command i get following
We faced same issue sometimes too.
1) Linux OOM killer kill your Cassandra process. You should find this event log
in /var/log/message.2) The JVM crashed. You should be able to find the
hs_err_pid file under /tmp folder, if you didn't specify the location when you
started your JVM.
We still
The meta information stored on behalf of CQL must exist on all nodes and must
update all nodes as well.
What table type is that meta information stored in? And is it possible we can
use that same type of table?
After all, this makes M/R blazingly fast to do local lookups in the database
(and
We had hs_err_pid files moths ago and it was happening every 6 days or so and
we switched to this JVM and we have not seen one since(including today)…that
worked for us at least.
java version 1.6.0_41
Java(TM) SE Runtime Environment (build 1.6.0_41-b02)
Java HotSpot(TM) 64-Bit Server VM (build
On Wed, Sep 18, 2013 at 3:09 PM, Hiller, Dean dean.hil...@nrel.gov wrote:
The meta information stored on behalf of CQL must exist on all nodes and
must update all nodes as well.
What table type is that meta information stored in? And is it possible we
can use that same type of table?
It's
For any website just starting out, the load initially is minimal grows
with a slow pace initially. People usually start with their MySQL based
sites with a single server(***that too a VPS not a dedicated server)
running as both app server as well as DB server usually get too far with
this setup
You might be interested in this:
http://mail-archives.apache.org/mod_mbox/cassandra-user/201308.mbox/%3ccaeqobhpav25pcgjfwbkmd1rzxvrif94e6lpybpj3mu_bqn9...@mail.gmail.com%3E
M.
W dniu 18.09.2013 15:34, Ertio Lew pisze:
For any website just starting out, the load initially is minimal grows
I really like this idea. I can create a new cluster and have it replicate
the old one, after it finishes I can remove the original.
Any good resource that explains how to add a new datacenter to a live
single dc cluster that anybody can recommend?
On Wed, Sep 18, 2013 at 9:58 AM, Chris
I have a column family contains time series events, all columns have a 24
hour TTL and gc_grace_seconds is currently 20 days. There is a TimeUUID in
part of the key.
It takes 15 days to repair the entire ring.
Consistency is not my main worry. Speed is. We currently write to this CF at
http://www.datastax.com/documentation/cassandra/1.2/webhelp/index.html#cassandra/operations/ops_add_dc_to_cluster_t.html
This is a basic outline.
On 09/18/2013 10:32 AM, Juan Manuel Formoso wrote:
I really like this idea. I can create a new cluster and have it replicate
the old one, after it
Hi Christopher,
in 2.0 gc_grace should be capped by TTL anyway: see CASSANDRA-4917
cheers,
Christian
On Wed, Sep 18, 2013 at 4:29 PM, Christopher Wirt chris.w...@struq.comwrote:
I have a column family contains time series events, all columns have a 24
hour TTL and gc_grace_seconds is
For future references, a blog post on this topic.
http://rustyrazorblade.com/2013/09/cassandra-faq-can-i-start-with-a-single-node/
On Wed, Sep 18, 2013 at 6:38 AM, Michał Michalski mich...@opera.com wrote:
You might be interested in this:
Awesome, thanks!
A few final questions:
1) Can I change the Snitch in the live source cluster? I'm using
SimpleSnitch, I'd change it to GossipingPropertyFileSnitch (in preparation
for changing the replication strategy when the new cluster is up and
running).
2) Can I have different Partitioners
Hi,
The idea behind Cassandra is not the same as for MySQL. First of all
you can't get fault tolerance with one node. I don't think Cassandra
nodes are more prone to be unavailable, but by using replication you
can get more availability right away. If you have multiple instances
when you start
OpsCenter's writes for monitoring data will show up in the request/latency
graphs yes. 100/sec may be reasonable depending on the number of nodes and
columnfamilies OpsCenter is monitoring.
On Wed, Sep 18, 2013 at 7:15 AM, Alexander Shutyaev shuty...@gmail.comwrote:
Hi all!
We have
Is there a vanilla cassandra sqoop driver for importing data into hadoop? I
know datastax cassandra comes with the utility however i'm interested in
vanilla cassandra.
Many thanks.
Hello to all
i am using counter columns in cassandra cluster with 3 nodes.
all 3 nodes are up and synchronized with ntp timeserver , same with client.
I am using libthrift java client.
Current problem i am having is that part of writes to counter columns
simply disappears ( most of time different
You might want to do some stuff in the application layer. If you can deal
with deleted deletes in the application layer, you can reduce your gc-grace
period.
On Wed, Sep 18, 2013 at 7:42 AM, horschi hors...@gmail.com wrote:
Hi Christopher,
in 2.0 gc_grace should be capped by TTL anyway: see
1. Always in cassandra up your file descriptor limits on linux and even in
0.7 that was the recommendation so cassandra could open tons of files
2. We use 50M for our LCS with no performance issues. We had it 10M on our
previous with no issues but a huge amount of files of course with our
We have set up a 24 node (m1.xlarge nodes, 1.7 TB per node) cassandra
cluster on Amazon EC2 :
version=1.2.9
replication factor = 2
snitch=EC2Snitch
placement_strategy=NetworkTopologyStrategy (with 12 nodes each in 2
availability zones)
Background on our use-case :
We plan on using hadoop with
Thanks for the quick reply. We've already upped the ulimit as high as our
Linux distro allows us to ( around 1.8 million ).
I have a follow-up question. I see that the size of individual nodes in
your use case is quite massive. Does the safe number vary widely based on
differences in underlying
Sorry, bad bad typo…..300G is what I meant.
Cassandra heavily advises to stay under 1T per node or you run into big
troubles and most people stay under 500G per node.
Later,
Dean
From: Jayadev Jayaraman jdisal...@gmail.commailto:jdisal...@gmail.com
Reply-To:
Hello Pradeep,
Let me try to help you, I faced a similar issue, too.
Thing is I was told selecting all the records at once is not an ideal approach.
No matter how strong the hardware is an arbitrary upward adjusted RPC time out
would not help, whatever value you give to it, the ‘SELECT *’
This article looks like it came out just one month ago or not even
http://blog.cloudera.com/blog/2013/08/how-to-select-the-right-hardware-for-your-new-hadoop-cluster/
And recommends 12-24 1-4TB disks in a JBOD configuration. I know hadoop is
used a lot in analytics but can also be used in some
Besides making sure the datacenter name is the same in the
cassandra-rackdc.properties file and the one originally created (datacenter1),
what else do I have to take into account?
Can I do a rolling restart or should I kill the entire cluster and then
startup one at a time?
--
*Juan Manuel
Here is a problem:
My customer has a 45Megabit connection to their off-site DR data
center. They have about 500G worth of data. That connection is shared.
Needless to say this is not an optimal configuration.
To replicate all that in real time it'll take a week.
My primary cluster is 4
Hi - During a write heavy load, the tpstats show the following -
Message type Dropped
RANGE_SLICE 0
READ_REPAIR 0
BINARY 0
READ 0
MUTATION 65570
_TRACE 0
The analysis on https://issues.apache.org/jira/browse/CASSANDRA-5727 will
be of interest.
As of 1.2.9 160mb is the new default for LCS.
On Wed, Sep 18, 2013 at 3:35 PM, Jayadev Jayaraman jdisal...@gmail.comwrote:
m1.xlarge ( total ephemeral volume size 1.7TB ) is the most widely used
node
On Wed, Sep 18, 2013 at 3:43 PM, Kanwar Sangha kan...@mavenir.com wrote:
what does the request_response signify ? That the node accepted the
message but was not able to process it in the timeout ?
**
Yes, I'm pretty sure it's referring to requests that the node dropped when
acting as a
Hi,
When I started with cassandra I had originally set it up to use tokens. I
then migrated to vnodes (using shuffle), but my cluster isn't balanced
(http://imgur.com/73eNhJ3).
What steps can I take to balance my cluster?
Thanks,
Nimi
OpsCenter only supports vnodes minimally at this point.
More specifically, it chooses a random token that a node owns in order to
display that node on the ring. So a vnode cluster will always appear
unbalanced in OpsCenter. Your cluster is probably balanced fine, but
'nodetoo status' should
This isn't the case. I noticed the error because of some unusual hotspotting.
`nodetool status` also shows the cluster is unbalanced.
root@cass1:~# nodetool status
Datacenter: 129
===
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- AddressLoad Tokens Owns
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