Re: How to install an older minor release?

Hi Oleksandr, Yes, that was always the case. All older versions are removed from Debian repo index :( From: Oleksandr Shulgin Reply-To: "user@cassandra.apache.org" Date: Tuesday, April 2, 2019 at 20:04 To: User Subject: How to install an older minor release? Hello, We've just noticed that

Re: New node insertion methods

Hi Vsevolod, > Are there any workarounds to speed up the process? (e.g. doing cleanup only > after all 4 new nodes joined cluster), or inserting multiple nodes > simultaneously with specific settings? e.g. doing cleanup only after all 4 new nodes joined cluster === allowed inserting multiple

Re: Maximum memory usage reached

e is the severity, level INFO. Generally, I don’t recommend running Cassandra on only 2GB ram or for small datasets that can easily fit in memory. Is there a reason why you’re picking Cassandra for this dataset? On Thu, Mar 7, 2019 at 8:04 AM Kyrylo Lebediev mailto:klebed...@conductor.com>> wr

Maximum memory usage reached

Hi All, We have a tiny 3-node cluster C* version 3.9 (I know 3.11 is better/stable, but can’t upgrade immediately) HEAP_SIZE is 2G JVM options are default All setting in cassandra.yaml are default (file_cache_size_in_mb not set) Data per node – just ~ 1Gbyte We’re getting following errors

RE: Java 11 support in Cassandra 4.0 + Early Testing and Feedback

As many people use Oracle JDK, I think it worth mentioning that according Oracle Support Roadmap there are some changes in their policies for Java 11 and above (http://www.oracle.com/technetwork/java/eol-135779.html). In particular: “Starting with Java SE 9, in addition to providing Oracle JDK

RE: Re:RE: data not beening syncd in different nodes

0 and yes,we are inserting data with TTL=60 seconds we have 200 vehicles and updating this table every 5 or 10 seconds; At 2018-08-31 17:10:50, "Kyrylo Lebediev" mailto:kyrylo_lebed...@epam.com.INVALID>> wrote: Looks like you're querying the table at CL = ONE which is default f

RE: data not beening syncd in different nodes

Looks like you're querying the table at CL = ONE which is default for cqlsh. If you run cqlsh on nodeX it doesn't mean you retrieve data from this node. What this means is that nodeX will be coordinator, whereas actual data will be retrieved from any node, based on token range + dynamic snitch

Re: Extending Cassandra on AWS from single Region to Multi-Region

Hi, There is an instruction how to switch to a different snitch in datastax docs: https://docs.datastax.com/en/cassandra/3.0/cassandra/operations/opsSwitchSnitch.html Personally I haven't tried to change Ec2 to Ec2Multi, but my understanding is that as long as 'dc' and 'rack' values are left

Re: Compression Tuning Tutorial

of room for improvement though :) On Thu, Aug 9, 2018 at 5:36 AM Kyrylo Lebediev wrote: Thank you Jon, great article as usually! One topic that was discussed in the article is filesystem cache which is traditionally leveraged for data caching in Cassandra (with row-caching disabled by default

Re: Compression Tuning Tutorial

Thank you Jon, great article as usually! One topic that was discussed in the article is filesystem cache which is traditionally leveraged for data caching in Cassandra (with row-caching disabled by default). IIRC mmap() is used. Some RDBMS and NoSQL DB's as well use direct I/O + async I/O +

Re: dynamic_snitch=false, prioritisation/order or reads from replicas

e / Spain The Last Pickle - Apache Cassandra Consulting http://www.thelastpickle.com 2018-08-06 22:27 GMT+01:00 Kyrylo Lebediev mailto:kyrylo_lebed...@epam.com.invalid>>: Thank you for replying, Alain! Better use of cache for 'pinned' requests explains good the case when CL=ONE. But i

Re: dynamic_snitch=false, prioritisation/order or reads from replicas

com<mailto:al...@thelastpickle.com> France / Spain The Last Pickle - Apache Cassandra Consulting http://www.thelastpickle.com 2018-08-04 15:37 GMT+02:00 Kyrylo Lebediev mailto:kyrylo_lebed...@epam.com.invalid>>: Hello! In case when dynamic snitching is enabled data is read from

Re: Hinted Handoff

Small gc_grace_seconds value lowers max allowed node downtime, which is 15 minutes in your case. After 15 minutes of downtime you'll need to replace the node, as you described. This interval looks too short to be able to do planned maintenance. So, in case you set larger value for

Re: How to downloading Cassandra 3.11.0 and 3.11.2 binaries for ubuntu

Go to: http://dl.bintray.com/apache/cassandra/pool/main/c/cassandra/ download deb packages for the versions you need and install them by dpkg. Regards, Kyrill From: R1 J1 Sent: Saturday, August 4, 2018 4:56:56 PM To: user@cassandra.apache.org Subject: How to

dynamic_snitch=false, prioritisation/order or reads from replicas

Hello! In case when dynamic snitching is enabled data is read from 'the fastest replica' and other replicas send digests for CL=QUORUM/LOCAL_QUORUM . When dynamic snitching is disabled, as the concept of the fastest replica disappears, which rules are used to choose from which replica to read

Re: Performance impact of using NetworkTopology with 3 node cassandra cluster in One DC

There are two factors in terms of Cassandra that determine what's called network topology: datacenter and rack. rack - it's not necessarily a physical rack, it's rather a single point of failure. For example, in case of AWS one availability zone is usually chosen to be a Cassandra rack.

Re: What will happen after adding another data disk

Also it worth noting, that usage of JBOD isn't recommended for older Cassandra versions, as there are known issues with data imbalance on JBOD. iirc JBOD data imbalance was fixed in some 3.x version (3.2?) For older versions creation one large filesystem on top md or lvm device seems to be a

Re: compaction: huge number of random reads

ou should test lowering your compression chunk size on the table and disabling read ahead. This sounds like it might just be a case of read amplification. On Tue., 8 May 2018, 05:43 Kyrylo Lebediev, <kyrylo_lebed...@epam.com<mailto:kyrylo_lebed...@epam.com>> wrote: Dear Experts, I'm observin

compaction: huge number of random reads

Dear Experts, I'm observing strange behavior on a cluster 2.1.20 during compactions. My setup is: 12 nodes m4.2xlarge (8 vCPU, 32G RAM) Ubuntu 16.04, 2T EBS gp2. Filesystem: XFS, blocksize 4k, device read-ahead - 4k /sys/block/vxdb/queue/nomerges = 0 SizeTieredCompactionStrategy After

Re: 3.11.2 io.netty.channel.unix.FileDescriptor.readAddress(...)(Unknown Source)

Hi! You are talking about messages like below, right? INFO [epollEventLoopGroup-2-8] 2018-05-05 16:57:45,537 Message.java:623 - Unexpected exception during request; channel = [id: 0xa4879fdd, L:/10.175.20.112:9042 - R:/10.175.20.73:2508] io.netty.channel.unix.Errors$NativeIoException:

Re: Host not available

First of all you need to identify what's the bottleneck in your case. First things to check: 1) jvm - heap is too small for such workloads Enable GC logging in /etc/cassandra/cassandra-env.sh, then analyze its output during workload. In case you observe messages about long pauses or Full

Re: copy from one table to another

Thank you, Rahul! From: Rahul Singh <rahul.xavier.si...@gmail.com> Sent: Saturday, April 21, 2018 3:02:11 PM To: user@cassandra.apache.org Subject: Re: copy from one table to another That’s correct. On Apr 21, 2018, 5:05 AM -0400, Kyrylo Lebediev <kyr

Re: copy from one table to another

table has a different Guid — doing a hard link may work as long as the sstable dir’s guid is he same as the newly created table in the system schema. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Apr 19, 2018, 10:41 AM -0500, Kyrylo Lebediev <kyrylo_lebed...@epam.com>, wrote: T

Re: copy from one table to another

Apr 16, 2018, 4:21 PM -0500, Kyrylo Lebediev <kyrylo_lebed...@epam.com>, wrote: Thanks, Ali. I just need to copy a large table in production without actual copying by using hardlinks. After this both tables should be used independently (RW). Is this a supported way or not? Reg

Re: copy from one table to another

laints and to improve our customer service, email communications may be monitored and telephone calls may be recorded. Kyrylo Lebediev <kyrylo_lebed...@epam.com> 04/16/2018 10:37 AM Please respond to user@cassandra.apache.org To "user@cassandra.apache.org" <user@

Re: copy from one table to another

Any issues if we: 1) create an new empty table with the same structure as the old one 2) create hardlinks ("ln without -s"): .../-/--* ---> .../-/--* 3) run nodetool refresh -- newkeyspacename newtable and then query/modify both tables independently/simultaneously? In theory, as SSTables

Re: Adding disk to operating C*

Niclas, Here is Jeff's comment regarding this: https://stackoverflow.com/a/31690279 From: Niclas Hedhman Sent: Friday, March 9, 2018 9:09:53 AM To: user@cassandra.apache.org; Rahul Singh Subject: Re: Adding disk to operating C* I am curious

Re: uneven data movement in one of the disk in Cassandra

Not sure where I heard this, but AFAIK data imbalance when multiple data_directories are in use is a known issue for older versions of Cassandra. This might be the root-cause of your issue. Which version of C* are you using? Unfortunately, don't remember in which version this imbalance issue

Re: Amazon Time Sync Service + ntpd vs chrony

regards, Michael On 03/08/2018 04:15 AM, Kyrylo Lebediev wrote: > Hi! > > Recently Amazon announced launch of Amazon Time Sync Service > (https://aws.amazon.com/blogs/aws/keeping-time-with-amazon-time-sync-service/) > and now it's AWS-recommended way for time sync on EC2 instance

Amazon Time Sync Service + ntpd vs chrony

Hi! Recently Amazon announced launch of Amazon Time Sync Service (https://aws.amazon.com/blogs/aws/keeping-time-with-amazon-time-sync-service/) and now it's AWS-recommended way for time sync on EC2 instances (https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html). It's stated

Re: Rocksandra blog post

Thanks for sharing, Dikang! Impressive results. As you plugged in different storage engine, it's interesting how you're dealing with compactions in Rocksandra? Is there still the concept of immutable SSTables + compaction strategies or it was changed somehow? Best, Kyrill

Re: How do counter updates work?

Hello! Can't answer your question but there is another one: "why do we need to maintain counters with their known limitations (and I've heard of some issues with implementation of counters in Cassandra), when there exist really effective uuid generation algorithms which allow us to generate

Re: vnodes: high availability

addad.com> Sent: Thursday, January 18, 2018 12:49:02 AM To: user Subject: Re: vnodes: high availability I *strongly* recommend disabling dynamic snitch. I’ve seen it make latency jump 10x. dynamic_snitch: false is your friend. On Jan 17, 2018, at 2:00 PM, Kyrylo Lebediev <kyrylo_le

Re: Cassandra filter with ordering query modeling

Hi! Partition key (Id in your case) must be in WHERE cause if not using indexes (but indexes should be used carefully, not like in case of relational DB's). Also, only columns which belong to primary key ( = partition key + clustering key) can be used in WHERE in such cases. That's why 2nd and

Re: JMX metrics for CL

Thank you so much, Eric! From: Eric Evans <john.eric.ev...@gmail.com> Sent: Wednesday, February 28, 2018 6:26:23 PM To: user@cassandra.apache.org Subject: Re: JMX metrics for CL On Tue, Feb 27, 2018 at 2:26 AM, Kyrylo Lebediev <kyrylo_lebed...

Re: JMX metrics for CL

the CL and increment the according metric. Then, in cassandra-env.sh you could specify to use your class using -Dcassandra.custom_query_handler_class. HTH, Horia On tis, 2018-02-27 at 08:26 +, Kyrylo Lebediev wrote: Hello! Is it possible to get counters from C* side regarding CQL q

Re: Cassandra on high performance machine: virtualization vs Docker

In terms of Cassandra, rack is considered as single point of failure. So, using some rack-aware snitch (GossipingPropertyFileSnitch would be the best for your case) Cassandra won't place multiple replicas of the same range in the same rack. Basically, there are two requirements that should be

Re: Is it possible / makes it sense to limit concurrent streaming during bootstrapping new nodes?

ommissioning the ones with 256 will be absolute hell. You can only do this by adding a new DC and retiring the old. On Feb 24, 2018, at 2:26 AM, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto:kyrylo_lebed...@epam.com>> wrote: > By the way, is it possible to migrate towards to

Re: Is it possible / makes it sense to limit concurrent streaming during bootstrapping new nodes?

> By the way, is it possible to migrate towards to smaller token ranges? What > is the recommended way doing so? - Didn't see this question answered. I think, be easiest way to do this is to add new C* nodes with lower vnodes (8, 16 instead of default 256) then decom old nodes with

Re: Missing 3.11.X cassandra debian packages

Yes, it's a 'known issue' with the style of Debian repos management. Personally, I don't understand why all versions of except the latest one are intentionally removed from repo index. Because if we had several versions of a package in the repo, anyway 'apt-get install cassandra

Re: Best approach to Replace existing 8 smaller nodes in production cluster with New 8 nodes that are bigger in capacity, without a downtime

roach to Replace existing 8 smaller nodes in production cluster with New 8 nodes that are bigger in capacity, without a downtime You can also create a new DC and then terminate old one. Sent from my iPhone > On Feb 20, 2018, at 2:49 PM, Kyrylo Lebediev <kyrylo_lebed...@epam.com> wrote:

Re: Best approach to Replace existing 8 smaller nodes in production cluster with New 8 nodes that are bigger in capacity, without a downtime

Hi, Consider using this approach, replacing nodes one by one: https://mrcalonso.com/2016/01/26/cassandra-instantaneous-in-place-node-replacement/ Regards, Kyrill From: Leena Ghatpande Sent: Tuesday, February 20, 2018 10:24:24 PM

Re: Cassandra Needs to Grow Up by Version Five!

Agree with you, Daniel, regarding gaps in documentation. --- At the same time I disagree with the folks who are complaining in this thread about some functionality like 'advanced backup' etc is missing out of the box. We all live in the time where there are literally tons of open-source tools

Re: Hints folder missing in Cassandra

Hi, Not sure what could be the reason, but the issue is obvious: directory /var/lib/cassandra/hints is missing or cassandra user doesn't have enough permissions on it. Regards, Kyrill From: test user Sent: Wednesday, February 7, 2018

Re: Cassandra 2.1: replace running node without streaming

From: Kyrylo Lebediev <kyrylo_lebed...@epam.com> Sent: Saturday, February 3, 2018 12:23:15 PM To: User Subject: Re: Cassandra 2.1: replace running node without streaming Thank you Oleksandr, Just tested on 3.11.1 and it worked for me (you may see the logs

Re: Cassandra 2.1: replace running node without streaming

same doubts before seeing it worked for the first time. -- Alex Am 03.02.2018 um 08:19 schrieb Oleksandr Shulgin <oleksandr.shul...@zalando.de<mailto:oleksandr.shul...@zalando.de>>: On 3 Feb 2018 02:42, "Kyrylo Lebediev" <kyrylo_lebed...@epam.com<mailto:kyrylo_leb

Re: Cassandra 2.1: replace running node without streaming

? Regards, Kyrill From: Oleksandr Shulgin <oleksandr.shul...@zalando.de> Sent: Friday, February 2, 2018 4:26:30 PM To: User Subject: Re: Cassandra 2.1: replace running node without streaming On Fri, Feb 2, 2018 at 3:15 PM, Kyrylo Lebediev <kyrylo_lebed...

Cassandra 2.1: replace running node without streaming

Hello All! I've got a pretty standard task - to replace a running C* node [version 2.1.15, vnodes=256, Ec2Snitch] (IP address will change after replacement, have no control over it). There are 2 ways stated in C* documentation how this can be done: 1) Add a new node, than 'nodetool

Re: Unable to change IP address from private to public

Haven't tried this by myself, but I suspect that in order to add public addresses for existing nodes for inter-dc communication, following method might work (just my guess): - take a node, shutdown C* there, change it's private IP, add public IP, update cassandra.yaml accordingly (the same

Re: vnodes: high availability

o a DC migration to a new DC with a better configuration of snitch/replication strategy/racks/tokens. On 16 January 2018 at 21:54, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto:kyrylo_lebed...@epam.com>> wrote: Thank you for this valuable info, Jon. I guess both you and Alex are ref

Re: vnodes: high availability

ly a lot of us wouldn't remember enough math to know how to approach it. If you want to get out of this situation you'll need to do a DC migration to a new DC with a better configuration of snitch/replication strategy/racks/tokens. On 16 January 2018 at 21:54, Kyrylo Lebediev <kyrylo_le

Re: question about nodetool decommission

Hi Jerome, I don't know reason for this, but compactions run during 'nodetool decommission'. What C* version you are working with? What is the reason you're decommissioning the node? Any issues with it? Can you see any errors/warnings in system.log on the node being decommissioned? Pending

Re: vnodes: high availability

be some imbalance, the amount of imbalance depends on luck, unfortunately. I’m interested to hear your results using 4 tokens, would you mind letting the ML know your experience when you’ve done it? Jon On Jan 16, 2018, at 9:40 AM, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto:kyrylo_l

Re: vnodes: high availability

On Jan 16, 2018, at 2:02 AM, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto:kyrylo_lebed...@epam.com>> wrote: ...to me it sounds like 'C* isn't that highly-available by design as it's declared'. More nodes in a cluster means higher probability of simultaneous node failures. And

Re: vnodes: high availability

at's something you must consider both when designing your cluster (how it is segmented, how operations are performed), and when designing your apps (how you will use the driver, how your apps will react to failure). Cheers, On Tue, Jan 16, 2018 at 11:03 AM Kyrylo Lebediev <kyrylo_lebed...@epa

Re: vnodes: high availability

e case that any 2 nodes going down result in a loss of QUORUM for some token range. On 15 January 2018 at 19:59, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto:kyrylo_lebed...@epam.com>> wrote: Thanks Alexander! I'm not a MS in math too) Unfortunately. Not sure, but it seems to m

Re: vnodes: high availability

but the odds will get slightly different). That makes maintenance predictable because you can shut down as many nodes as you want in a single rack without losing QUORUM. Feel free to correct my numbers if I'm wrong. Cheers, On Mon, Jan 15, 2018 at 5:27 PM Kyrylo Lebediev <kyrylo_lebed...@epam.c

Re: vnodes: high availability

a degraded cluster and operate temporarily in downgraded consistency mode http://docs.datastax.com/en/latest-java-driver-api/com/datastax/driver/core/policies/DowngradingConsistencyRetryPolicy.html - Rahul On Mon, Jan 15, 2018 at 10:04 AM, Kyrylo Lebediev <kyrylo_lebed...@epam.com<mailto

vnodes: high availability

Hi, Let's say we have a C* cluster with following parameters: - 50 nodes in the cluster - RF=3 - vnodes=256 per node - CL for some queries = QUORUM - endpoint_snitch = SimpleSnitch Is it correct that 2 any nodes down will cause unavailability of a keyrange at CL=QUORUM? Regards,

RE: Reg :- Multiple Node Cluster set up in Virtual Box

Nandan, There are several options available how this can be done. For example, you may configure 2 network adapters per each VM: 1) NAT: in order the VM to have access to the Internet 2) Host-only Adapter - for internode communication setup (listen_address, rpc_address). Static IP configuration