Re: EC2 instance recommendations

i3 instances will undoubtedly give you more meat for buck - easily 40K+ iops whereas on the other hand EBS maxes out at 20K PIOPS which is highly expensive (at times they can cost you significantly more than cost of instance). But they have ephemeral local storage and data is lost once instance is

Re: How to find dataSize at client side?

Hi, If you were to know the batch size on client side to make sure it does not get above the 5kb limit, so that you can "limit the number of statements in a batch", I would suspect you do not need batch at all right ? See https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/ As

How to find dataSize at client side?

* WARN [SharedPool-Worker-1] 2017-05-22 20:28:46,204 BatchStatement.java (line 253) Batch of prepared statements for [site24x7.wm_rawstats_tb, site24x7.wm_rawstats] is of size 6122, exceeding specified threshold of 5120 by 1002* We are frequently getting this message in logs, so I wanted to

Re: EC2 instance recommendations

> Oh, so all the data is lost if the instance is shutdown or restarted (for that instance)? When you restart the OS, you're technically not shutting down the instance. As long as the instance isn't stopped / terminated, your data is fine. I ran my databases on ephemeral storage for years

Re: EC2 instance recommendations

We are running on I3s since they came out. NVMe SSDs are really fast and I managed to push them to 75k IOPs. As Bhuvan mentioned the i3 storage is ephemeral. If you can work around it and plan for failure recovery you are good to go. I ran Cassandra on m4s before and had no problems with EBS

Re: EC2 instance recommendations

Oh, so all the data is lost if the instance is shutdown or restarted (for that instance)? If we take a naïve approach to backing up the directory, and restoring it, if we ever have to bring down the instance and back up, will that work as a strategy? Data is only kept around for 2 days and is

Re: EC2 instance recommendations

I'm experimenting with bcache to see about using the ephemeral storage as a cache backed with EBS. Not sure if that makes sense in your use case though. On Tue, May 23, 2017 at 9:43 AM Jonathan Haddad wrote: > > Oh, so all the data is lost if the instance is shutdown or

Re: EC2 instance recommendations

Thanks! So, I assume that as long we make sure we never explicitly “shutdown” the instance, we are good. Are you also saying we won’t be able to snapshot a directory with ephemeral storage and that is why EBS is better? We’re just finding that to get a reasonable amount of IOPS (gp2) out of EBS

Re: EC2 instance recommendations

Exactly. You can easily build a solid backup/restore with snapshots and automate it in case all hell breaks loose. EBS volumes are expensive right now and with i3 you get much more IOPs and a reasonable disk size for 1/2 or 1/3 the price. Best, Matija On Tue, May 23, 2017 at 1:29 PM, Gopal,

Re: Slowness in C* cluster after implementing multiple network interface configuration.

Hi, I never used version 2.0.x but I think port 7000 isn't enough. Try enable: 7000 inter-node 7001 SSL inter-node 9042 CQL 9160 Thrift is enable in that version And **In Cassandra.yaml, add property “broadcast_address”. = local ipv4 **In Cassandra.yaml, change “listen_address” to

Re: EC2 instance recommendations

Another option that I like the idea of but never see used unfortunately is using ZFS, with EBS for storage and the SSD ephemeral drive as L2Arc. You'd get the performance of ephemeral storage with all the features of EBS. Something to consider. On Tue, May 23, 2017 at 10:30 AM Gopal, Dhruva

Re: EC2 instance recommendations

Note that EBS durability isn't perfect, you cannot rely on them entirely: https://aws.amazon.com/ebs/details/ "Amazon EBS volumes are designed for an annual failure rate (AFR) of between 0.1% - 0.2%, where failure refers to a complete or partial loss of the volume, depending on the size and

Re: InternalResponseStage low on some nodes

This is really atypical. What about nodetool compactionstats? crontab jobs in each node like nodetool repair, etc? Also security these 2 nodes have the same ports open? Same configuration, same JVM params? nodetool ring normal? Cheers. On 23-05-2017 20:11, Andrew Jorgensen wrote: > Hello,

Re: Bottleneck for small inserts?

Are the 3 sending clients maxed out? Are you seeing JVM GC pauses? On 2017-05-22 14:02 (-0700), Eric Pederson wrote: > Hi all: > > I'm new to Cassandra and I'm doing some performance testing. One of things > that I'm testing is ingestion throughput. My server setup is:

Re: Bottleneck for small inserts?

When you are running a stress test, 1-1 match client to server won't saturate a cluster. I would go closer to 3-5 clients per server, so 10-15 clients against your 3 node cluster. Patrick On Tue, May 23, 2017 at 4:18 PM, Jeff Jirsa wrote: > > Are the 3 sending clients maxed

InternalResponseStage low on some nodes

Hello, I will preface this and say that all of the nodes have been running for about the same amount of time and were not restarted before running nodetool tpstats. This is more for my understanding that anything else but I have a 20 node cassandra cluster running cassandra 3.0.3. I have 0 read

Re: EC2 instance recommendations

By that do you mean it’s like bootstrapping a node if it fails or is shutdown and with a RF that is 2 or higher, data will get replicated when it’s brought up? From: Cogumelos Maravilha Date: Tuesday, May 23, 2017 at 1:52 PM To: "user@cassandra.apache.org"

Re: EC2 instance recommendations

I think this is overstating it. If the instance ever stops you'll lose the data. That means if the server crashes for example, or if Amazon decides your instance requires maintenance. On Tue, May 23, 2017 at 10:30 AM Gopal, Dhruva wrote: > Thanks! So, I assume that as

Re: EC2 instance recommendations

Yes we can only reboot. But using rf=2 or higher it's only a node fresh restart. EBS is a network attached disk. Spinning disk or SSD is almost the same. It's better take the "risk" and use type i instances. Cheers. On 23-05-2017 21:39, sfesc...@gmail.com wrote: > I think this is overstating

Re: memtable_allocation_type on Cassandra 2.1.x

Thanks Akhil for response. I have set memtable_allocation_type as Off-heap. But cassandra 2.1.x does not allow to set *memtable_heap_space_in_mb: 0.* It mentions , we need to assign some positive value to heap space. In such case, will memtable still use jvm heap space. Can anyone suggest below

Re: EC2 instance recommendations

We run on both ephemeral and persistent on AWS. Ephemeral storage is the local storage attached to the server host. We don't have extreme write & read, so EBS is fine. If youever shut down the EC2 instance, your data is guaranteed to be gone because AWS moves your VM to another host after every

Re: Bottleneck for small inserts?

Hi, Change to *|durable_writes = false|* And please post the results. Thanks. On 05/22/2017 10:08 PM, Jonathan Haddad wrote: > How many CPUs are you using for interrupts? > > http://www.alexonlinux.com/smp-affinity-and-proper-interrupt-handling-in-linux > > Have you tried making a flame