Re: more nodes than vnodes

nks a lot Hannu, > > really helpful! But isn't that crazy expensive? adding a vnode means that > every vnode in the cluster will have a different range of tokens which means > a lot of data will need to be moved around. > > Thanks again, > Luca > > > &g

Re: more nodes than vnodes

> ok, that makes sense, but does the partitioner add vnodes? is the number of > vnodes fixed in a cluster? > > On Wed, Jun 15, 2022 at 12:10 AM Hannu Kröger <mailto:hkro...@gmail.com>> wrote: > Hey, > > num_tokens is tokens per node. > > So in you

Re: more nodes than vnodes

Hey, num_tokens is tokens per node. So in your case you would have 15 vnodes altogether. Cheers, Hannu > On 15. Jun 2022, at 10.08, Luca Rondanini wrote: > > Hi all, > > I'm just trying to understand better how cassandra works. > > My understanding is that, once set, the number of vnodes

Re: Data not persisted in Cassandra docker

You need to mount volumes from the host system or docker volumes to container to have data persisted. See section "Where to Store Data” in https://hub.docker.com/_/cassandra Hannu > On 9. Mar 2020, at 11.25, Valentina Ivanova wrote: > > Hello! > > I am

Re: Cassandra going OOM due to tombstones (heapdump screenshots provided)

It means that you are using 5-10GB of memory just to hold information about tables. Memtables hold the data that is written to the database until those are flushed to the disk, and those happen when memory is low or some other threshold is reached. Every table will have a memtable that takes

Re: Cassandra going OOM due to tombstones (heapdump screenshots provided)

IIRC there is an overhead of about 1MB per table which you have about 5000-1 => 5GB - 10GB overhead of just having that many tables. To me it looks like that you need to increase the heap size and later potentially work on the data models to have less tables. Hannu > On 29. Jan 2020, at

Re: [E] bug in cluster key push down

No, I think it was originally correct. If partition key has multiple parts, then you need parenthesis around parts of partition key. Hannu > On 13. Jan 2020, at 14.30, Saha, Sushanta K > wrote: > >> primary key (partition, clustering1, clustering2) >> >> So, the partitioning key has three

Re: Exact use case for CustomPayloads in v4 protocol version

For example using it to pass distributed tracing token to Cassandra which can then later be used to track operations end to end across the whole stack from api entry point to Cassandra query traces. This explains how it is done:

Re: Securing cluster communication

I would start checking this page: http://cassandra.apache.org/doc/latest/operating/security.html Then move to this: https://thelastpickle.com/blog/2015/09/30/hardening-cassandra-step-by-step-part-1-server-to-server.html Cheers, Hannu > Marc Richter kirjoitti 28.6.2019 kello 16.55: > > Hi

Re: Disable Truststore CA check for internode_encryption

the OP is after. Hannu > Jeff Jirsa kirjoitti 28.2.2019 kello 9.01: > > That’s client to server - internode is different > > Don’t think it’s possible without code modifications - please opens JIRA > > -- > Jeff Jirsa > > >> On Feb 27, 20

Re: Disable Truststore CA check for internode_encryption

Is server encryption option ”require_client_auth: false” what you are after? Hannu > Jai Bheemsen Rao Dhanwada kirjoitti 28.2.2019 kello > 1.57: > > Hello, > > Is it possible to disable truststore CA check for the cassandra > internode_encyrption? if yes, is there a config property to do

Restore a table with dropped columns to a new cluster fails

been other similar tickets that have been apparently closed but based on my test with 3.11.4, the issue still persists. Best Regards, Hannu Kröger

Potential bootstrap failure bugs

s CQL connections. 3) If I run “bootstrap resume” twice after failure or once before bootstrap has failed, nodetool is reporting that bootstrap is already done (same goes to logs). Which is not true. Bootstrap is ongoing. What do you think, should I open tickets about these? Best regards, Hannu K

Re: Scale SASI index

You shouldn’t need to. You just scale up and run ”nodetool cleanup” and that will take care of it. Hannu > onmstester onmstester kirjoitti 18.9.2018 kello 8.52: > > By adding new nodes to cluster, should i rebuild SASI indexes on all nodes ? > >

Re: [EXTERNAL] full text search on some text columns

ps://github.com/strapdata/elassandra (I haven't > tested this plugin) > > 2018-08-01 12:17 GMT+03:00 Hannu Kröger : >> 3.11.1 plugin works with 3.11.2. But yes, original maintainer is not >> maintaining the project anymore. At least not actively. >> >> Hannu &

Re: [EXTERNAL] full text search on some text columns

3.11.1 plugin works with 3.11.2. But yes, original maintainer is not maintaining the project anymore. At least not actively. Hannu > Ben Slater kirjoitti 1.8.2018 kello 7.16: > > We (Instaclustr) will be submitting a PR for 3.11.3 support for > cassandra-lucene-index once 3.11.3 is

Re: Reading cardinality from Statistics.db failed

What version of Cassandra are you running? There is a bug in 3.10.0 and certain 3.0.x that occurs in certain conditions and corrupts that file. Hannu > Vitali Dyachuk kirjoitti 25.7.2018 kello 10.48: > > Hi, > I have noticed in the cassandra system.log that there is some issue with >

Re: Compaction out of memory

Could the problem be that the process ran out of file handles? Recommendation is to tune that higher than the default. Hannu > onmstester onmstester kirjoitti 12.7.2018 kello 12.44: > > Cassandra crashed in Two out of 10 nodes in my cluster within 1 day, the > error is: > > ERROR

Re: rebuild on running node

You have just some extra data on those machines where you ran rebuild. Compaction will eventually take care of that. Nothing really harmful if you have the disk space available. Hannu > Randy Lynn kirjoitti 5.7.2018 kello 19.19: > > Anyone ever make stupid mistakes? :) > > TL/DR: I ran

Re: Problem with dropped mutations

s not upto mark! > > You can also check if network isn't dropping packets (ifconfig -a tool) + > storage (dstat tool) isn't reporting too slow disks. > > Cheers/Asad > > > -----Original Message- > From: Hannu Kröger [mailto:hkro...@gmail.com] > Sent: Tuesday

Problem with dropped mutations

Hello, We have a cluster with somewhat heavy load and we are seeing dropped mutations (variable amount and not all nodes have those). Are there some clear trigger which cause those? What would be the best pragmatic approach to start debugging those? We have already added more memory which

Re: Client ID logging

Hmm, I think that by default not but you can create a hook to log that. Create a wrapper for PasswordAuthenticator class for example and use that. Or if you don’t use authentication you can create your own query handler. Hannu > James Lovato kirjoitti 21.5.2018 kello

Re: Error after 3.1.0 to 3.11.2 upgrade

Hi, Did you check replication strategy and amounts of replicas of system_auth keyspace? Hannu > Abdul Patel kirjoitti 12.5.2018 kello 5.21: > > No applicatiom isnt impacted ..no complains .. > Also its an 4 node cluster in lower non production and all are on same >

Re: Does LOCAL_ONE still replicate data?

Writes are always replicated to all nodes (if they are online). LOCAL_ONE in writes just means that client will get an “OK” for the write only after at least node in local datacenter has acknowledged that the write is done. If all local replicas are offline, then the write will fail even if it

Re: upgrade from 3.9 to 3.11.2

; 倪项菲/ David Ni > 中移德电网络科技有限公司 > Virtue Intelligent Network Ltd, co. > > Add: 2003,20F No.35 Luojia creative city,Luoyu Road,Wuhan,HuBei > Mob: +86 13797007811|Tel: + 86 27 5024 2516 > > 发件人: Hannu Kröger <hkro...@gmail.com> > 发送时间: 2018年5月3日 15:00 > 收件人:

Re: upgrade from 3.9 to 3.11.2

Hello, it never hurts to run “nodetool upgradesstables" after the upgrade. It’s a no-op if there is nothing to upgrade. Hannu > On 3 May 2018, at 09:57, Xiangfei Ni wrote: > > Hi Community > I have a question regarding upgrading Cassandra from 3.9 to 3.11.2, > Do I

Re: GUI clients for Cassandra

Ah, you are correct! However, it’s not being updated anymore AFAIK. Do you know if it support the latest 3.x features? SASI, MV, etc. ? Hannu > On 24 Apr 2018, at 03:45, Christophe Schmitz > wrote: > > Hi Hannu ;) > > > >>> I have been asked many times that

GUI clients for Cassandra

Hello everyone! I have been asked many times that what is a good GUI client for Cassandra. DevCenter is not available anymore and DataStax has a DevStudio but that’s for DSE only. Are there some 3rd party GUI tools that you are using a lot? I always use the command line client myself. I have

Re: Nodetool Repair --full

Hi Jonathan, If you want to repair just one node (for example if it has been down for more than 3h), run “nodetool repair -full” on that node. This will bring all data on that node up to date. If you want to repair all data on the cluster, run “nodetool repair -full -pr” on each node. This

Re: What versions should the documentation support now?

In my opinion, a good documentation should somehow include version specific pieces of information. Whether it is nodetool command that came in certain version or parameter for something or something else. That would very useful. It’s confusing if I see documentation talking about 4.0 specifics

Re: Row cache functionality - Some confusion

> On 12 Mar 2018, at 14:45, Rahul Singh wrote: > > I may be wrong, but what I’ve read and used in the past assumes that the > “first” N rows are cached and the clustering key design is how I change what > N rows are put into memory. Looking at the code, it seems

Re: Row cache functionality - Some confusion

il.com> wrote: > > What’s the goal? How big are your partitions , size in MB and in rows? > > -- > Rahul Singh > rahul.si...@anant.us > > Anant Corporation > > On Mar 12, 2018, 6:37 AM -0400, Hannu Kröger <hkro...@gmail.com>, wrote: >> Anyone? >> >

Re: Row cache functionality - Some confusion

Anyone? > On 4 Mar 2018, at 20:45, Hannu Kröger <hkro...@gmail.com> wrote: > > Hello, > > I am trying to verify and understand fully the functionality of row cache in > Cassandra. > > I have been using mainly two different sources for information: > https:/

Re: vnodes: high availability

If this is a universal recommendation, then should that actually be default in Cassandra? Hannu > On 18 Jan 2018, at 00:49, Jon Haddad wrote: > > I *strongly* recommend disabling dynamic snitch. I’ve seen it make latency > jump 10x. > > dynamic_snitch: false is your

Re: How do counter updates work?

:34, Javier Pareja <pareja.jav...@gmail.com> wrote: > > Doesn't cassandra have TIMEUUID for these use cases? > > Anyways, hopefully someone can help me better understand possible delays when > writing a counter. > > F Javier Pareja > > On Mon, Mar 5, 2018 at 1:54

Re: How do counter updates work?

Traditionally auto increment counters have been used to generate SQL row IDs. This is what Kyrylo probably is here referring to. Cassandra counters are better tracking e.g. usage patterns, web site visitors, statistics, etc. For accurate counting (e.g. for generating IDs) those counters are

Row cache functionality - Some confusion

Hello, I am trying to verify and understand fully the functionality of row cache in Cassandra. I have been using mainly two different sources for information:

Re: How to Parse raw CQL text?

If this is needed functionality, shouldn’t that be available as a public method or something? Maybe write a patch etc. ? > Ariel Weisberg kirjoitti 26.2.2018 kello 18.47: > > Hi, > > I took a similar approach and it worked fine. I was able to build a tool that > parsed

Re: vnodes status verification

Hello, you can always run “nodetool ring” to see all tokens. Hannu > On 26 Feb 2018, at 12:32, Ivan Iliev wrote: > > Hello C* Gurus, > > I am quite new to cassandra so I am struggling over the concent of vnodes and > how to verify if those are properly enabled on my

Re: Setting min_index_interval to 1?

Wouldn’t that still try to read the index on the disk? So you would just potentially have all keys on the memory and on the disk and reading would first happen in memory and then on the disk and only after that you would read the sstable. So you wouldn’t gain much, right? Hannu > On 2 Feb

Re: Repair fails for unknown reason

We have run restarts on the cluster and that doesn’t seem to help at all. We ran repair separately for each table that seems to go through usually but running a repair on a keyspace doesn’t. Anything anyone? Hannu > On 3 Jan 2018, at 23:24, Hannu Kröger <hkro...@gmail.com> wrote: &

Re: Repair fails for unknown reason

il.com> > wrote: > > hi Hannu, > > I think some of the repairs are hanging there. please restart all the nodes > in the cluster and start the repair > > > Thanks > Nanda > > On Wed, Jan 3, 2018 at 9:35 AM, Hannu Kröger <hkro...@gmail.com > <mailto

Re: Repair fails for unknown reason

Additional notes: 1) If I run the repair just on those tables, it works fine 2) Those tables are empty Hannu > On 3 Jan 2018, at 18:23, Hannu Kröger <hkro...@gmail.com> wrote: > > Hello, > > Situation is as follows: > > Repair was started on node X on this keys

Repair fails for unknown reason

Hello, Situation is as follows: Repair was started on node X on this keyspace with —full —pr. Repair fails on node Y. Node Y has debug logging on (DEBUG on org.apache.cassandra) and I’m looking at the debug.log. I see following messages related to this repair request: --- DEBUG

Re: Nodetool compactionstats hangs

Hi, Sure! I attached the jstack dumps on the ticket. Hannu On 19 December 2017 at 14:38:45, Jeff Jirsa (jji...@gmail.com) wrote: Can you grab a thread dump with jstack as well? -- Jeff Jirsa On Dec 19, 2017, at 3:32 AM, Hannu Kröger <hkro...@gmail.com> wrote: Hi, I opened a ticket

Nodetool compactionstats hangs

Hi, I opened a ticket about nodetool compactionstats hanging: https://issues.apache.org/jira/browse/CASSANDRA-14130 The root cause seems to be JMX metric fetching hanging. I was able to replicate it on this problematic like this: Welcome to JMX terminal. Type "help" for available commands.

TWCS on partitions spanning multiple time windows

Hi, I have been reading a bit about TWCS to understand how it functions. Current assumption: TWCS uses same tombstone checks as any other compaction strategy to make sure that it doesn’t remove tombstones unless it is safe to do so. Scenario 1: So let’s assume that I have a tables like this:

Re: Upgrade using rebuild

If you want to do a version upgrade, you need to basically do follow node by node: 0) stop repairs 1) make sure your sstables are at the latest version (nodetool upgradesstables can do it) 2) stop cassandra 3) update cassandra software and update cassandra.yaml and cassandra-env.sh files 4) start

Re: Best approach to prepare to shutdown a cassandra node

Hi, Drain should be enough. It stops accepting writes and after that cassandra can be safely shut down. Hannu On 12 October 2017 at 20:24:41, Javier Canillas (javier.canil...@gmail.com) wrote: Hello everyone, I have some time working with Cassandra, but every time I need to shutdown a node

Re: [RELEASE] Apache Cassandra 3.11.1 released

Hi, Isn’t that already here: http://dl.bintray.com/apache/cassandra/dists/311x/main/binary-amd64/ ? Hannu On 11 October 2017 at 16:33:27, Lucas Benevides (lu...@maurobenevides.com.br) wrote: Hello Michael Schuler, When will this version become available for upgrade from apt-get? I visited the

Re: Materialized views stability

gt; you're probably better off not using them. > > Thanks, > > Blake > > On October 2, 2017 at 6:55:52 AM, Hannu Kröger (hkro...@gmail.com) wrote: > > Hello, > > I have seen some discussions around Materialized Views and stability of > that functionality. > > There are

Materialized views stability

Hello, I have seen some discussions around Materialized Views and stability of that functionality. There are some open issues around repairs:

Re: network down between DCs

Hi, That’s correct. You need to run repairs only after a node/DC/connection is down for more then max_hint_window_in_ms. Cheers, Hannu On 21 September 2017 at 11:30:44, Peng Xiao (2535...@qq.com) wrote: Hi there, We have two DCs for a Cassandra Cluster,if the network is down less than 3

Re: Historical data movement to other cluster

Hi, If you have that data in different tables, then it’s relatively straight forward operations of loading only certain tables with sstableloader. If not, then you could use spark to read and filter data from one cluster and store that into another cluster. Hannu On 13 September 2017 at

Re: Rebalance a cassandra cluster

Hi, you should make sure that token range is evenly distributed if you have a single token configured per node. You can use e.g. this tool to calculate tokens: https://www.geroba.com/cassandra/cassandra-token-calculator/ Also, make sure that none of the partitions in your data model are hotspots

Do not use Cassandra 3.11.0+ or Cassandra 3.0.12+

Hello, Current latest Cassandra version (3.11.0, possibly also 3.0.12+) has a race condition that causes Cassandra to create broken sstables (stats file in sstables to be precise). Bug described here: https://issues.apache.org/jira/browse/CASSANDRA-13752 This change might be causing it (but not

Re: Corrupted commit log prevents Cassandra start

quick fix, I'd recommend: - Delete the affected log file - Start the node - Run a full-range (not -pr) repair on that node 2017-07-07 10:57 GMT+02:00 Hannu Kröger <hkro...@gmail.com>: > Hello, > > We had a test server crashing for some reason (not related to Cassandra > probably)

Corrupted commit log prevents Cassandra start

Hello, We had a test server crashing for some reason (not related to Cassandra probably) and now when trying to start cassandra, it gives following error: ERROR [main] 2017-07-06 09:29:56,140 JVMStabilityInspector.java:82 - Exiting due to error while processing commit log during initialization.

Re: Repair on system_auth

You can also stop repair using JMX without restarting. There are scripts to do that. Hannu > On 6 Jul 2017, at 23.24, ­Fay Hou [Storage Service] > wrote: > > There is a bug on repair system_auth keyspace. We just skip the repair on > system_auth. Yes. it is ok to kill

Re: Linux version update on DSE

:56 AM, Nitan Kainth <ni...@bamlabs.com> wrote: Right, we are just upgrading Linux on AWS. C* will remain at same version. On Jun 26, 2017, at 6:05 PM, Hannu Kröger <hkro...@gmail.com> wrote: I understood he is updating linux, not C* Hannu On 27 June 2017 at 02:04:34, Jonath

Re: Hints files are not getting truncated

Hi, First of all, I don’t know why they get delivered so slowly. However, if your gc grace seconds is the default 10 days then those hints from May are not needed and could/should be truncated. If the hint delivery is causing problems, then one option is that you could just disable it and rely

Re: Linux version update on DSE

need to take a node down, upgrade the C* version, then start it back up. Jon On Mon, Jun 26, 2017 at 3:56 PM Nitan Kainth <ni...@bamlabs.com> wrote: > It's vnodes. We will add to replace new ip in yaml as well. > > Thank you. > > Sent from my iPhone > > > On Jun 26,

Re: Linux version update on DSE

Looks Ok. Step 1.5 would be to stop cassandra on existing node but apart from that looks fine. Assuming you are using same configs and if you have hard coded the token(s), you use the same. Hannu > On 26 Jun 2017, at 23.24, Nitan Kainth wrote: > > Hi, > > We are

Re: Incorrect quorum count in driver error logs

Just to be sure: you have only one datacenter configured in Cassandra? Hannu > On 27 Jun 2017, at 0.02, Rutvij Bhatt wrote: > > Hi guys, > > I observed some odd behaviour with our Cassandra cluster the other day while > doing some maintenance operation and was wondering if

Re: SASI index on datetime column does not filter on minutes

Hello, I tried the same thing with 3.10 which I happened to have at hand and that seems to work. cqlsh:test> select lastname,firstname,dateofbirth from individuals where dateofbirth < '2001-01-01T10:00:00' and dateofbirth > '2000-11-18 17:59:18'; lastname | firstname | dateofbirth

Re: Node replacement strategy with AWS EBS

'm replacing the >> old node? >> >> As for the plan I outlined earlier, is this more for DR scenarios where I >> have lost a node due to hardware failure and I need to recover the data in >> a safe manner by requesting a stream from the other replicas? Am I >>

Re: Node replacement strategy with AWS EBS

, "Cassandra automatically realizes that have just effectively changed IP address” —> are you sure C* will take care of IP change as is? How will it know which token range to be assigned to this new IP address? On Jun 13, 2017, at 10:51 AM, Hannu Kröger <hkro...@gmail.com> wrote: Cassandra

Re: Node replacement strategy with AWS EBS

Hello, I think that’s not the optimal way to handle it. If you are just attaching the same EBS volume to a new node you can do like this: 1) nodetool drain on old 2) stop cassandra on old 3) Attach EBS to new node 4) Start Cassandra on new node Cassandra automatically realizes that have just

Re: Is DataStax's DSE better than cassandra's free open source for a newbie developer's good start for cassandra?

Hello, DSE is commercial and costs money to use in production. More info from DataStax: http://www.datastax.com/products/subscriptions RPMs are currently not available for the latest version. There is 3.0.13 but newer than that are not available

Weirdest problem on this mailing list

Hello, For some reason the emails I sent to this Cassandra email list end up to PayPal support email. Can some list admin check if there is something weird in the list configuration or if some funny person added PayPal support address to mailing list? Cheers, Hannu

Re: Cassandra Server 3.10 unable to Start after crash - commitlog needs to be removed

I have seen this happen as well. Deleting commit logs helps to Cassandra start but of course if you are very unlucky you might lose some data. Hannu > On 19 May 2017, at 18.13, Haris Altaf wrote: > > Hi All, > I am using Cassandra 3.10 for my project and whenever my

Re: sstablesplit - status

Basically meaning that if you run major compaction (=nodetool compact), you will end up with even bigger file and that is likely to never get compacted without running major compaction again. And therefore not recommended for production system. Hannu > On 17 May 2017, at 19:46, Nitan Kainth

Re: Range deletes, wide partitions, and reverse iterators

e records since they are sorted. My understanding > would be something like: > > 1) read sstable 2 > 2) read the range tombstone > 3) skip records from sstable2 and sstable1 within the range boundaries > 4) read remaining records from sstable1 > 5) no records, return > > On

Re: Range deletes, wide partitions, and reverse iterators

ORDER BY timeid DESC; > > > > On Tue, May 16, 2017 at 5:17 PM, Stefano Ortolani <ostef...@gmail.com > <mailto:ostef...@gmail.com>> wrote: > Yes, that was my intention but I wanted to cross-check with the ML and the > devs keeping an eye on it first. > > On

Re: Range deletes, wide partitions, and reverse iterators

formation re the clustering key ranges, and the > data is clustering key sorted, I would expect a linear scan not to be > necessary. > > On Tue, May 16, 2017 at 3:46 PM, Hannu Kröger <hkro...@gmail.com > <mailto:hkro...@gmail.com>> wrote: > Well, as mentioned, probabl

Re: Decommissioned node cluster shows as down

That’s weird. I thought decommission would ultimately remove the node from the cluster because the token(s) should be removed from the ring and data should be streamed to new owners. “DN” is IMHO not a state where the node should end up in. Hannu > On 16 May 2017, at 19:05, suraj pasuparthy

Re: Range deletes, wide partitions, and reverse iterators

w can you read a partition in reverse? > > Sent from my iPhone > > > On May 16, 2017, at 9:20 AM, Hannu Kröger <hkro...@gmail.com > > <mailto:hkro...@gmail.com>> wrote: > > > > Well, I’m guessing that Cassandra doesn't really know if the range > > tomb

Re: Range deletes, wide partitions, and reverse iterators

> > Sent from my iPhone > >> On May 16, 2017, at 9:20 AM, Hannu Kröger <hkro...@gmail.com> wrote: >> >> Well, I’m guessing that Cassandra doesn't really know if the range tombstone >> is useful for this or not. >> >> In many cases it might be t

Re: Range deletes, wide partitions, and reverse iterators

Well, I’m guessing that Cassandra doesn't really know if the range tombstone is useful for this or not. In many cases it might be that the partition contains data that is within the range of the tombstone but is newer than the tombstone and therefore it might be still be returned. Scanning

Re: Reg:- DSE 5.1.0 Issue

Hello, DataStax is probably more than happy answer your particaly DataStax Enterprise related questions here (I don’t know if that is 100% right place but…): https://support.datastax.com/hc/en-us This mailing list is for open source Cassandra and DSE

Re: Exceptions when upgrade from 2.1.14 to 2.2.5

Hello, It seems that commit log is broken. One way to fix this would be to remove commit logs and then restart. This will cause you to lose the writes that were in the commit log but hopefully the data is in other nodes. In the future to avoid this: before you kill Cassandra, run “nodetool

Re: Slow writes and Frequent timeouts

It would help to know what kind queries are slow. Hannu > On 17 Apr 2017, at 18:42, Akshay Suresh wrote: > > Hi > > I have set up a cassandra cluster of 8 nodes. > > I am using Apache Cassandra 3.9 > > While using cassandra-stress tool for load testing, I am

Re: Making a Cassandra node cluster unique

Hi, Cluster name should be unique because with misconfiguration you might make the nodes connect to either of the cluster and then you will have nodes is wrong clusters. Theoretically it can work with same names as well but to be on the safe side, make the cluster names unique. Hannu On Wed, 5

Re: Can I do point in time recover using nodetool

Yes, It's possible. I haven't seen good instructions online though. The Cassandra docs are quite bad as well. I think I asked about it in this list and therefore I suggest you check the mailing list archive as Mr. Roth suggested. Hannu On Wed, 8 Mar 2017 at 10.50, benjamin roth

Re: Any way to control/limit off-heap memory?

If bloom filters are taking too much memory, you can adjust bloom filters: https://docs.datastax.com/en/cassandra/2.1/cassandra/operations/ops_tuning_bloom_filters_c.html Hannu > On 4 Mar 2017, at

Current data density limits with Open Source Cassandra

Hello, Back in the day it was recommended that max disk density per node for Cassandra 1.2 was at around 3-5TB of uncompressed data. IIRC it was mostly because of heap memory limitations? Now that off-heap support is there for certain data and 3.x has different data storage format, is that

Re: Strange issue wherein cassandra not being started from cron

One possible reason is that cassandra process gets different user when run differently. Check who owns the data files and check also what gets written into the /var/log/cassandra/system.log (or whatever that was). Hannu > On 11 Jan 2017, at 16.42, Ajay Garg wrote: > >

Re: Is this normal!?

Just to understand: What exactly is the problem? Cheers, Hannu > On 11 Jan 2017, at 16.07, Cogumelos Maravilha > wrote: > > Cassandra 3.9. > > nodetool status > Datacenter: dc1 > === > Status=Up/Down > |/ State=Normal/Leaving/Joining/Moving > --

Point in time restore

Hello, Are there any guides how to do a point-in-time restore for Cassandra? All I have seen is this: http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/configuration/configLogArchive_t.html

Re: cassandra documentation (Multiple datacenter write requests) question

Looks like the graph is wrong. Hannu > On 22 Nov 2016, at 15.43, CHAUMIER, RAPHAËL > wrote: > > Hello everyone, > > I don’t know if you have access to DataStax documentation. I don’t understand > the example about Multiple datacenter write requests >

Re: Improving performance where a lot of updates and deletes are required?

Also in they are being read before compaction: http://docs.datastax.com/en/cql/3.1/cql/cql_using/use_expire_c.html Hannu > On 8 Nov 2016, at 16.36, DuyHai Doan wrote: > > "Does TTL also cause

Re: Transparent Fail-Over for Java Driver to survive Cluster Rolling

update the cluster? I would assume that QUORUM (replication > of 3) might not always go through? > > > > On Mon, Oct 24, 2016 at 2:09 PM, Hannu Kröger <hkro...@gmail.com > <mailto:hkro...@gmail.com>> wrote: > Hi, > > Once the client is connected, it wil

Re: Transparent Fail-Over for Java Driver to survive Cluster Rolling

Hi, Once the client is connected, it will automatically connect to many nodes in the cluster. Therefore once the app is running the amount of contact points doesn’t matter and if you have consistency level < ALL (or QUORUM where replication factor is <= 2), your app should tolerate rolling

Re: Row cache not working

If I remember correctly row cache caches only N rows from the beginning of the partition. N being some configurable number. See this link which is suggesting that: http://www.datastax.com/dev/blog/row-caching-in-cassandra-2-1 Br, Hannu > On 4 Oct 2016, at 1.32, Edward Capriolo

Re: Maximum number of columns in a table

I do agree on that. > On 15 Sep 2016, at 16:23, DuyHai Doan <doanduy...@gmail.com> wrote: > > I'd advise anyone against using the old native secondary index ... You'll get > poor performance (that's the main reason why some people developed SASI). > > On Thu, Sep 15,

Re: Maximum number of columns in a table

Hi, The ‘old-fashioned’ secondary indexes do support index of collection values: https://docs.datastax.com/en/cql/3.1/cql/ddl/ddlIndexColl.html Br, Hannu > On 15 Sep 2016, at 15:59, DuyHai Doan wrote: > >

Re: Is it safe to change RF in this situation?

epair is trying to fix as > RF=2 or still trying to fix like RF=3? > > On Thu, Sep 8, 2016 at 2:53 PM, Hannu Kröger <hkro...@gmail.com > <mailto:hkro...@gmail.com>> wrote: > Yep, you can fix it by running repair or even faster by changing the > consistency le

Re: Is it safe to change RF in this situation?

anging RF from 2 to 3, and did see the empty > result rate is going higher. I assume that "If the LOCAL_ONE read hit the > new replica which is not there yet, the CQL query will return nothing." Is my > assumption correct? > > On Thu, Sep 8, 2016 at 11:49 AM, H

Re: Is it safe to change RF in this situation?

Hi, If you change RF=2 -> 3 first, the LOCAL_ONE reads might hit the new replica which is not there yet. So I would change LOCAL_ONE -> LOCAL_QUORUM first and then change the RF and then run the repair. LOCAL_QUORUM is effectively ALL in your case (RF=2) if you have just one DC, so you can

Re: Query regarding spark on cassandra

saw the stdout from web-ui of spark, and the query along with true was > printed for both the queries.". > The statements were correct as seen on the UI. > Thanks, > Siddharth Verma > > > > On Thu, Apr 28, 2016 at 1:22 PM, Hannu Kröger <hkro...@gmail.com > <m

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