ApacheCon Europe 2019

Hi, Do we have any plans for dedicated Apache Cassandra track or sessions at ApacheCon Berlin in Oct 2019? CFP closes 26 May, 2019. ThanksAnuj Wadehra

Re: Upgrade to v3.11.3

Hi Shalom, Just a suggestion. Before upgrading to 3.11.3 make sure you are not impacted by any open crtitical defects especially related to RT which may cause data loss e.g.14861. Please find my response below: The upgrade process that I know of is from 2.0.14 to 2.1.x (higher than 2.1.9 I

Cassandra Upgrade with Different Protocol Version

Hi, I woud like to know how people are doing rolling upgrade of Casandra clustes when there is a change in native protocol version say from 2.1 to 3.11. During rolling upgrade, if client application is restarted on nodes, the client driver may first contact an upgraded Cassandra node with v4

Re: [External] Re: Whch version is the best version to run now?

We evaluated both 3.0.x and 3.11.x. +1 for 3.11.2 as we faced major performance issues with 3.0.x. We have NOT evaluated new features on 3.11.x. Anuj Sent from Yahoo Mail on Android On Tue, 6 Mar 2018 at 19:35, Alain RODRIGUEZ wrote: Hello Tom, It's good to hear this

Re: LWT and non-LWT mixed

Hi Daniel, What is the RF and CL for Delete?Are you using asynchronous writes?Are you firing both statements from same node sequentially?Are you firing these queries in a loop such that more than one delete and LWT is fired for same partition? I think if you have the same client executing both

Re: 回复： 回复： tolerate how many nodes down in the cluster

Hi Peng,  Racks can be logical (as defined with RAC attribute in Cassandra configuration files) or physical (racks in server rooms).   In my view, for leveraging racks in your case, its important to understand the implication of following decisions: 1. Number of distinct logical RACs defined in

Re: 回复： tolerate how many nodes down in the cluster

error to the sender and then immediately delete the message. On 25 July 2017 at 03:06, Anuj Wadehra <anujw_2...@yahoo.co.in.invalid> wrote: Hi Peng,  Three things are important when you are evaluating fault tolerance and availability for your cluster: 1. RF2. CL3. Topology -  how data is re

Re: 回复： tolerate how many nodes down in the cluster

Hi Peng,  Three things are important when you are evaluating fault tolerance and availability for your cluster: 1. RF2. CL3. Topology -  how data is replicated in racks.  If you assume that N  nodes from ANY rack may fail at the same time,  then you can afford failure of RF-CL nodes and still be

RE: MUTATION messages were dropped in last 5000 ms for cross node timeout

t some number that may not be optimal.     Thank you again.       From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Thursday, July 20, 2017 12:17 PM To: ZAIDI, ASAD A <az1...@att.com>; user@cassandra.apache.org Subject: Re: MUTATION messages were dropped in last 5000 ms fo

Re: MUTATION messages were dropped in last 5000 ms for cross node timeout

Hi Asad,  You can do following things: 1.Increase memtable_flush_writers especially if you have a write heavy load.  2.Make sure there are no big gc pauses on your nodes. If yes,  go for heap tuning.  Please let us know whether above measures fixed your problem or not.  ThanksAnuj Sent from

Re: "nodetool repair -dc"

Hi,  I have not used dc local repair specifically but generally repair syncs all local tokens of the node with other replicas (full repair) or a subset of local tokens (-pr and subrange). Full repair with - Dc option should only sync data for all the tokens present on the node where the command

Re: private interface for interdc messaging

Hi,  I am not sure why you would want to connect clients on public interface. Are you making db calls from clients outside the DC?  Also, not sure why you expect two DCs to communicate on private networks unless they are two logical DCs within same physical DC.  Generally,  you configure multi

Re: Merkle trees requests hanging

Hi Jean,  Ensure that your firewall is not timing out idle connections. Nodes should time out idle connections first (using tcp keep alive settings before firewall does it). Please refer  http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/troubleshooting/trblshootIdleFirewall.html.  

Re: Cassandra Cluster Expansion Criteria

Hi Asad, First, you need to understand the factors impacting cluster capacity. Some of the important factors to be considered while doing capacity planning of Cassandra are: 1.  Compaction strategy: It impacts disk space requirements and IO/CPU/memory overhead for compactions. 2. Replication

Re: Restore Snapshot

Thanks Kurt. I think the main scenario which MUST be addressed by snapshot is Backup/Restore so that a node can be restored with minimal time and the lengthy procedure of boottsrapping with join_ring=false followed by full repair can be avoided. The plain restore snapshot + repair scenario

Re: Linux version update on DSE

Also, if you restore exactly same data with different IP, you may need to clear gossip state on the node. Anuj Sent from Yahoo Mail on Android On Tue, Jun 27, 2017 at 11:56 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi Nitan, I asked for adding autobootstrap false to avoid str

Re: Linux version update on DSE

Hi Nitan, I think it would be simpler to take one node down at a time and replace it by bringing the new node up after linux upgrade, doing same cassandra setup, using replace_address option and setting autobootstrap=false ( as data is already there). No downtime as it would be a rolling

Restore Snapshot

Hi, I am curious to know how people practically use Snapshot restore provided that snapshot restore may lead to inconsistent reads until full repair is run on the node being restored ( if you have dropped mutations in your cluster). Example: 9 am snapshot taken on all 3 nodes10 am mutation

Re: Hints files are not getting truncated

Hi Meg, max_hint_window_in_ms =3 hrs means that if a node is down/unresponsive for more than 3 hrs, hints would not be stored for it any further until it becomes responsive again. It should not mean that already stored hints would be truncated after 3 hours. Regarding connection timeouts

Re: Re-adding Decommissioned node

Hi Mark, Please ensure that the node is not defined as seed node in the yaml. Seed nodes don't bootstrap. ThanksAnuj On Tue, Jun 27, 2017 at 9:56 PM, Mark Furlong wrote: I have a node that has been decommissioned and it showed ‘UL’, the data volume and the

Re: Partition range incremental repairs

y were taking more like 8-9 hours. As I understand it, using incremental should have sped this process up as all three sets of data on each repair job should be marked as repaired however this does not seem to be the case. Any ideas? Chris On 6 Jun 2017, at 16:08, Anuj Wadehra <anujw_2...@yahoo.co.i

Re: Partition range incremental repairs

Hi Chris, Using pr with incremental repairs does not make sense. Primary range repair is an optimization over full repair. If you run full repair on a n node cluster with RF=3, you would be repairing each data thrice. E.g. in a 5 node cluster with RF=3, a range may exist on node A,B and C .

Re: Weird error: InvalidQueryException: unconfigured table table2

Ensure that all the nodes are on same schema version such that table2 schema is replicated properly on all the nodes. ThanksAnuj Sent from Yahoo Mail on Android On Sat, Mar 25, 2017 at 3:19 AM, S G wrote: Hi, I have a keyspace with two tables. I run a different

Repair while upgradesstables is running

Hi, What is the implication of running inc repair when all nodes have upgraded to new Cassandra rpm but parallel upgradesstables is still running on one or more of the nodes? So upgrade is like:1. Rolling upgrade of all nodes (rpm install)2. Parallel upgrade sstable on all nodes ( no issues

Incremental Repair

Hi, Our setup is as follows: 2 DCS with N nodes, RF=DC1:3,DC2:3, Hinted Handoff=3 hours, Incremental Repair scheduled once on every node (ALL DCs) within the gc grace period. I have following queries regarding incremental repairs: 1. When a node is down for X hours (where x > hinted handoff

Re: Is it possible to recover a deleted-in-future record?

DISCLAIMER: This is only my personal opinion. Evaluate the situation carefully and if you find below suggestions useful, follow them at your own risk. If I have understood the problem correctly, malicious deletes would actually lead to deletion of data.  I am not sure how everything is normal

Re: Read after Write inconsistent at times

Hi Charulata, Please share details on how data is being inserted and read.  Is the client which is reading the data same as the one which inserted it? Is the read happening only when insertion is successful? Are you using client timestamps? How did you verify that NTP is working properly? How

Re: Cluster scaling

Hi Branislav, I quickly went through the code and noticed that you are updating RF from code and expecting that Cassandra would automatically distribute replicas as per the new RF. I think this is not how it works. After updating the RF, you need to run repair on all the nodes to make sure that

Re: Disc size for cluster

Adding to what Benjamin said.. It is hard to estimate disk space if you are using STCS for a table where rows are updated frequently leading to lot of fragmentation. STCS may also lead to scenarios where tombstones are not evicted for long times. You may go live and everything goes well for

Re: Join_ring=false Use Cases

17:40, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: No responses yet :) Any C* expert who could help on join_ring use case and the concern raised? Thanks Anuj On Tue, 13 Dec, 2016 at 11:31 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, I need to understand the use case

Re: Join_ring=false Use Cases

No responses yet :) Any C* expert who could help on join_ring use case and the concern raised? Thanks Anuj On Tue, 13 Dec, 2016 at 11:31 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, I need to understand the use case of join_ring=false in case of node outages. As per

Re: Join_ring=false Use Cases

Can anyone help me with join_ring and address my concerns? Thanks Anuj On Tue, 13 Dec, 2016 at 11:31 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, I need to understand the use case of join_ring=false in case of node outages. As per https://issues.apache.org/jira/browse/CAS

Re: Configure NTP for Cassandra

synchronization using reliable external servers. There is no madate to setup your own pool of internal NTP servers for BETTER time synchronization. Thanks for your inputs.Anuj On Wed, 14 Dec, 2016 at 3:22 AM, Martin Schröder<mar...@oneiros.de> wrote: 2016-11-26 20:20 GMT+01:00 Anuj W

Re: Configure NTP for Cassandra

You might find more NTP experts on the NTP questions mailing list: http://lists.ntp.org/listinfo/questions On Tue, Dec 13, 2016 at 1:25 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: > Any NTP experts willing to take up these questions? > > Thanks > Anuj > > On Sun,

Re: Configure NTP for Cassandra

Any NTP experts willing to take up these questions? Thanks Anuj On Sun, 27 Nov, 2016 at 12:52 AM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, One popular NTP setup recommended for Cassandra users is described at  Thankshttps://blog.logentries.com/2014/03/synchronizing-

Join_ring=false Use Cases

Hi, I need to understand the use case of join_ring=false in case of node outages. As per https://issues.apache.org/jira/browse/CASSANDRA-6961, you would want join_ring=false when you have to repair a node before bringing a node back after some considerable outage. The problem I see with

Re: Single cluster node restore

Hi Petr, If data corruption means accidental data deletions via Cassandra commands, you have to restore entire cluster with latest snapshots. This may lead to data loss as there may be valid updates after the snapshot was taken but before the data deletion. Restoring single node with snapshot

Configure NTP for Cassandra

Hi, One popular NTP setup recommended for Cassandra users is described at  Thankshttps://blog.logentries.com/2014/03/synchronizing-clocks-in-a-cassandra-cluster-pt-2-solutions/ . Summary of article is:Setup recommends a dedicated pool of internal NTP servers which are associated as peers to

Re: Some questions to updating and tombstone

Hi Boying, I agree with Vladimir.If compaction is not compacting the two sstables with updates soon, disk space issues will be wasted. For example, if the updates are not closer in time, first update might be in a big table by the time second update is being written in a new small table. STCS

Re: Handle Leap Seconds with Cassandra

11/05/apache-cassandra-synchronization/. Ben   On Thu, 27 Oct 2016 at 10:18 Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi Ben, Thanks for your reply. We dont use timestamps in primary key. We rely on server side timestamps generated by coordinator. So, no functions at client side w

Re: Handle Leap Seconds with Cassandra

rouble even without leap seconds (clock drift, NTP inaccuracy etc).   On Thu, 20 Oct 2016 at 10:30 Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi, I would like to know how you guys handle leap seconds with Cassandra.  I am not bothered about the livelock issue as we are using appropri

Handle Leap Seconds with Cassandra

Hi, I would like to know how you guys handle leap seconds with Cassandra.  I am not bothered about the livelock issue as we are using appropriate versions of Linux and Java. I am more interested in finding an optimum answer for the following question: How do you handle wrong ordering of multiple

Re: Cassandra installation best practices

Hi Mehdi, You can refer  https://docs.datastax.com/en/landing_page/doc/landing_page/recommendedSettings.html  . ThanksAnuj On Mon, 17 Oct, 2016 at 10:20 PM, Mehdi Bada wrote: Hi all, It is exist some best practices when installing Cassandra on production

Re: Repair in Multi Datacenter - Should you use -dc Datacenter repair or repair with -pr

Hi Leena, Do you have a firewall between the two DCs? If yes, connection reset can be caused by Cassandra trying to use a TCP connection which is already closed by the firewall. Please make sure that you set high connection timeout at firewall. Also, make sure your servers are not overloaded.

Re: Repair in Multi Datacenter - Should you use -dc Datacenter repair or repair with -pr

Hi Leena, First thing you should be concerned about is : Why the repair -pr operation doesnt complete ? Second comes the question : Which repair option is best? One probable cause of stuck repairs is : if the firewall between DCs is closing TCP connections and Cassandra is trying to use such

Re: Multiple Network Interfaces in non-EC2

Hi Amir, I would like to understand your requirement first. Why do you need multiface interface configuration mentioned at http://docs.datastax.com/en/cassandra/3.x/cassandra/configuration/configMultiNetworks.html with single DC setup? As per my understanding, you could simply set listen

Re: Open File Handles for Deleted sstables

sandra service helped get rid of those files in our situation. thanksSai On Wed, Sep 28, 2016 at 3:15 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi, We are facing an issue where Cassandra has open file handles for deleted sstable files. These open file handles keep on increasi

Open File Handles for Deleted sstables

Hi, We are facing an issue where Cassandra has open file handles for deleted sstable files. These open file handles keep on increasing with time and eventually lead to disk crisis. This is visible via lsof command.  There are no Exceptions in logs.We are suspecting a race condition where

Re: Preferred IP is NULL

interface to private interface. NAT rule is needed due to CASSANDRA-9748 (No process listens on broadcast address). ThanksAnuj Sent from Yahoo Mail on Android On Mon, 22 Aug, 2016 at 11:55 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: We are using PropertyFileSnitch. ThanksAnuj

Re: Preferred IP is NULL

24 GMT-03:00 Anuj Wadehra <anujw_2...@yahoo.co.in>: Hi Paulo, I am aware of CASSANDRA-9748. It says that Cassandra only listens at listen_address and not broadcast_address. To overcome that I can add a NAT rule to route all traffiic on public IP to private IP.  But, why preferred IP is

Re: Preferred IP is NULL

of preferred IPs. ThanksAnuj On Sun, 21 Aug, 2016 at 7:10 PM, Paulo Motta<pauloricard...@gmail.com> wrote: See CASSANDRA-9748, I think it might be related. 2016-08-20 15:20 GMT-03:00 Anuj Wadehra <anujw_2...@yahoo.co.in>: Hi, We use multiple interfaces in multi DC setup.Broad

Preferred IP is NULL

Hi, We use multiple interfaces in multi DC setup.Broadcast address is public IP while listen address is private IP. I dont understand why prefeerred IP in peers table is null for all rows. There is very little documentation on the role of preferred IP and when it is set. As per code TCP

Re: Public Interface Failure in Multiple DC setup

Hi  Can someone take these questions? ThanksAnuj On Thu, 11 Aug, 2016 at 8:30 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, Setup: Cassandra 2.0.14 with PropertyFileSnitch. 2 Data Centers. Every node has broadcast address= Public IP (bond0) & listen address=Private

Public Interface Failure in Multiple DC setup

Hi, Setup: Cassandra 2.0.14 with PropertyFileSnitch. 2 Data Centers. Every node has broadcast address= Public IP (bond0) & listen address=Private IP (bond1). As per DataStax docs, (https://docs.datastax.com/en/cassandra/2.0/cassandra/configuration/configMultiNetworks.html), "For

Re: (C)* stable version after 3.5

Hi Alain, This caught my attention: "Also I am not sure if the 2.2 major version is something you can skip while upgrading through a rolling restart. I believe you can, but it is not what is recommended." Why do you think that skipping 2.2 is not recommended when NEWS.txt suggests otherwise?

Evict Tombstones with STCS

Hi, We are using C* 2.0.x . What options are available if disk space is too full to do compaction on huge sstables formed by STCS (created around long ago but not getting compacted due to min_compaction_threshold being 4). We suspect that huge space will be released when 2 largest sstables get

Re: Production Ready/Stable DataStax Java Driver

GAAJ [2]:  https://groups.google.com/a/lists.datastax.com/d/msg/java-driver-user/tOWZm4RVbm4/5E_aDAc8IAAJ On Sun, May 8, 2016 at 7:39 AM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi, Which DataStax Java Driver release is most stable (production ready) for Cassandra 2.1? ThanksAnuj -

RE: Inconsistent Reads after Restoring Snapshot

lt;sean_r_dur...@homedepot.com> wrote: https://docs.datastax.com/en/cassandra/2.0/cassandra/configuration/configLogArchive_t.html   Sean Durity   From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Wednesday, April 27, 2016 10:44 PM To: user@cassandra.apache.org Subject: RE: Inconsis

RE: Inconsistent Reads after Restoring Snapshot

etween the snapshot and the crash?     Sean Durity   From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Monday, April 25, 2016 10:26 PM To: User Subject: Inconsistent Reads after Restoring Snapshot   Hi,   We have 2.0.14. We use RF=3 and read/write at Quorum. Moreov

Re: Inconsistent Reads after Restoring Snapshot

s) in cassandra.yaml), start the node with -Dcassandra.join_ring=false and then run a repair on it. Have a look at https://issues.apache.org/jira/browse/CASSANDRA-6961 Best, Romain Le Mardi 26 avril 2016 4h26, Anuj Wadehra <anujw_2...@yahoo.co.in> a écrit : Hi, We have

Re: Upgrading to SSD

ld probably follow.  (Datastax's recommendations as well as AL tobey's tuning guide are great resources. https://tobert.github.io/pages/als-cassandra-21-tuning-guide.html ) Clint On Apr 23, 2016 3:05 PM, "Anuj Wadehra" <anujw_2...@yahoo.co.in> wrote: Hi We have a 3 no

Inconsistent Reads after Restoring Snapshot

Hi, We have 2.0.14. We use RF=3 and read/write at Quorum. Moreover, we dont use incremental backups. As per the documentation at  https://docs.datastax.com/en/cassandra/2.0/cassandra/operations/ops_backup_snapshot_restore_t.html  , if i need to restore a Snapshot on SINGLE node in a cluster, I

Re: Unable to reliably count keys on a thrift CF

Hi Carlos, Please check if the JIRA :  https://issues.apache.org/jira/browse/CASSANDRA-11467 fixes your problem. We had been facing row count issue with thrift cf / compact storage and this fixed it. Above is fixed in latest 2.1.14. Its a two line fix. So, you can also prepare a custom jar and

Re: StatusLogger is logging too many information

Hi, You can set the property gc_warn_threshold_in_ms in yaml.For example, if your application is ok with a 2000ms pause, you can set the value to 2000 such that only gc pauses greater than 2000ms will lead to gc and status log. Please refer

Upgrading to SSD

Hi We have a 3 node cluster of 2.0.14. We use Read/Write Qorum and RF is 3.  We want to move data and commitlog directory from a SATA HDD to SSD. We have planned to do a rolling upgrade. We plan to run repair -pr on all nodes  to sync data upfront and then execute following steps on each server

Re: Efficient Paging Option in Wide Rows

Hi, Can anyone take this question? ThanksAnuj Sent from Yahoo Mail on Android On Sat, 23 Apr, 2016 at 2:30 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: I think I complicated the question..so I am trying to put the question crisply.. We have a table defined with clustering key/

Re: Efficient Paging Option in Wide Rows

, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, I have a wide row index table so that I can fetch all row keys corresponding to a column value.  Row of index_table will look like: ColValue1:bucket1 >> rowkey1, rowkey2.. rowkeyn..ColValue1:bucketn>> rowkey1, rowkey2.. ro

Efficient Paging Option in Wide Rows

Hi, I have a wide row index table so that I can fetch all row keys corresponding to a column value.  Row of index_table will look like: ColValue1:bucket1 >> rowkey1, rowkey2.. rowkeyn..ColValue1:bucketn>> rowkey1, rowkey2.. rowkeyn We will have buckets to avoid hotspots. Row keys of main

Re: Migrating to CQL and Non Compact Storage

maybe people here can help you out. -- Jack Krupansky On Mon, Apr 11, 2016 at 10:39 AM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Any comments or suggestions on this one?  ThanksAnuj Sent from Yahoo Mail on Android On Sun, 10 Apr, 2016 at 11:39 PM, Anuj Wadehra<anujw_2...

Re: Migrating to CQL and Non Compact Storage

Any comments or suggestions on this one?  ThanksAnuj Sent from Yahoo Mail on Android On Sun, 10 Apr, 2016 at 11:39 PM, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi We are on 2.0.14 and Thrift. We are planning to migrate to CQL soon but facing some challenges. We have a cf with

Migrating to CQL and Non Compact Storage

Hi We are on 2.0.14 and Thrift. We are planning to migrate to CQL soon but facing some challenges. We have a cf with a mix of statically defined columns and dynamic columns (created at run time). For reading dynamic columns in CQL, we have two options: 1. Drop all columns and make the table

Re: DataStax OpsCenter with Apache Cassandra

On Sun, 10 Apr, 2016 at 10:42 PM, Jeff Jirsa<jeff.ji...@crowdstrike.com> wrote: It is possible to use OpsCenter for open source / community versions up to 2.2.x. It will not be possible in 3.0+ From: Anuj Wadehra Reply-To: "user@cassandra.apache.org" Date: Sunday, April 10,

DataStax OpsCenter with Apache Cassandra

Hi, Is it possible to use DataStax OpsCenter for monitoring Apache distributed Cassandra in Production?  OR  Is it possible to use DataStax OpsCenter if you are not using DataStax Enterprise in production? ThanksAnuj

Re: Does saveToCassandra work with Cassandra Lucene plugin ?

I used it with Java and there, every field of Pojo must map to column names of the table. I think someone with Scala syntax knowledge can help you better. ThanksAnuj Sent from Yahoo Mail on Android On Mon, 28 Mar, 2016 at 11:47 pm, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: W

Re: Does saveToCassandra work with Cassandra Lucene plugin ?

With my limited experience with Spark, I can tell you that you need to make sure that all columns mentioned in somecolumns must be part of CQL schema of table. ThanksAnuj Sent from Yahoo Mail on Android On Mon, 28 Mar, 2016 at 11:38 pm, Cleosson José Pirani de

Expiring Columns

Hi, I want to understand how Expiring columns work in Cassandra. Query:Documentation says that once TTL of a column expires, tombstones are created/ marked when the sstable gets compacted. Is there a possibility that a query (range scan/ row query) returns expired column data just because the

IOException: MkDirs Failed to Create in Spark

Hi We are using Spark with Cassandra. While using rdd.saveAsTextFile("/tmp/dr"), we are getting following error when we run the application with root access. Spark is able to create two level of directories but fails after that with Exception: 16/03/01 22:59:48 WARN TaskSetManager: Lost task

Re: how to read parent_repair_history table?

Hi Jimmy, We are on 2.0.x. We are planning to use JMX notifications for getting repair status. To repair database, we call forceTableRepairPrimaryRange JMX operation from our Java client application on each node. You can call other latest JMX methods for repair. I would be keen in knowing the

Re: Restart Cassandra automatically

Hi Subharaj, Cassandra is built to be a Fault tolerant distributed db and suitable for building HA systems. As Cassandra provides multiple replicas for the same data, if a single nide goes down in Production, it wont bring down the cluster. In my opinion, if you target to start one or more

Re: Debugging write timeouts on Cassandra 2.2.5

Thrift mostly) to 5 tables, between 6-1500 rows per batch. Mike On Thu, Feb 18, 2016 at 12:22 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Whats the GC overhead? Can you your share your GC collector and settings ? Whats your query pattern? Do you use secondary indexes, batches, in claus

Re: Debugging write timeouts on Cassandra 2.2.5

Whats the GC overhead? Can you your share your GC collector and settings ? Whats your query pattern? Do you use secondary indexes, batches, in clause etc? Anuj Sent from Yahoo Mail on Android On Thu, 18 Feb, 2016 at 8:45 pm, Mike Heffner wrote: Alain, Thanks for the

Re: Scenarios which need Repair

Hi, Can someone take this? ThanksAnuj On Mon, 8 Feb, 2016 at 11:44 pm, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi, Setup: We are on 2.0.14. We have some deployments with just one DC(RF:3) while others with two DCs (RF:3,RF:3). We ALWAYS use LOCAL_QUORUM for both

Re: Moving Away from Compact Storage

the sense of CQL static) column in your legacy table.  Just define a Scala case class to match this table and use Spark to dump the content to a new non compact CQL table On Tue, Feb 2, 2016 at 7:55 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Our old table looks like this from cql

Re: Moving Away from Compact Storage

creation script On Tue, Feb 2, 2016 at 3:48 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Thanks DuyHai !! We were also thinking to do it the "Spark" way but I was not sure that its would be so simple :) We have a compact storage cf with each row having some data in

Re: Moving Away from Compact Storage

s have the SAME structure (except for the COMPACT STORAGE clause), migration with Spark is a 2 lines of code On Mon, Feb 1, 2016 at 8:14 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi Whats the fastest and reliable way to migrate data from a Compact Storage table to Non-Comp

Re: Cassandra's log is full of mesages reset by peers even without traffic

Carlo "The best way to predict the future is to invent it" Alan Kay On Fri, Jan 29, 2016 at 11:02 AM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Hi Jean, Please make sure that your Firewall is not dropping TCP connections which are in use. Tcp keep alive on all nodes must be

Cqlsh hangs & closes automatically

My cqlsh prompt hangs and closes if I try to fetch just 100 rows using select * query. Cassandra-cli does the job. Any solution? ThanksAnuj

Re: Moving Away from Compact Storage

rstand what you mean by "dynamic columns". Given the CREATE TABLE script you gave earlier, there is nothing such as dynamic columns On Tue, Feb 2, 2016 at 8:01 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote: Will it be possible to read dynamic columns data from compact stor

Moving Away from Compact Storage

Hi Whats the fastest and reliable way to migrate data from a Compact Storage table to Non-Compact storage table? I was not able to find any command for dropping the compact storage directive..so I think migrating data is the only way...any suggestions? ThanksAnuj

Re: Cassandra's log is full of mesages reset by peers even without traffic

Hi Jean, Please make sure that your Firewall is not dropping TCP connections which are in use. Tcp keep alive on all nodes must be less than the firewall setting. Please refer to  https://docs.datastax.com/en/cassandra/2.0/cassandra/troubleshooting/trblshootIdleFirewall.html  for details on TCP

Re: Read operations freeze for a few second while adding a new node

Hi Lorand, Do you see any different gc pattern during these 20 seconds? In 2.0.x, memtable create lot of heap pressure. So in a way, reads are not isolated from writes. Frankly speaking, I would have accepted 20 second slowness as scaling is one time activity. But may be your business case

Re: Using TTL for data purge

, 23 Jan, 2016 at 12:16 am, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Give a deep thought on your use case. Different user tables/types may have different purge strategy based on how frequently a user account type is usually accessed, whats the user count for each user type

Re: Using TTL for data purge

pm, Anuj Wadehra<anujw_2...@yahoo.co.in> wrote: Hi Joseph, I am personally in favour of Second approach because I dont want to do lot of IO just because a user is accessing a site several times a day.  Options I see: 1.If you are on SSDs, Test LCS and update TTL of all columns at each

Re: Using TTL for data purge

Hi Joseph, I am personally in favour of Second approach because I dont want to do lot of IO just because a user is accessing a site several times a day.  Options I see: 1.If you are on SSDs, Test LCS and update TTL of all columns at each access. This will make sure that the system can tolerate

Re: Production with Single Node

And I think in a 3 node cluster, RAID 0 would do the job instead of RAID 5 . So you will need less storage to get same disk space. But you will get protection against disk failures and infact entire node failure. Anuj Sent from Yahoo Mail on Android On Sat, 23 Jan, 2016 at 10:30 am, Anuj

Re: Production with Single Node

I think Jonathan said it earlier. You may be happy with the performance for now as you are using the same commitlog settings that you use in large clusters. Test the new setting recommended so that you know the real picture. Or be prepared to lose some data in case of failure. Other than

Re: Run Repairs when a Node is Down

reated to allow repairing ranges with down replicas with a special flag (--force). If you're interested please add comments there and/or propose a patch. Thanks, Paulo 2016-01-17 1:33 GMT-03:00 Anuj Wadehra <anujw_2...@yahoo.co.in>: Hi  We are on 2.0.14,RF=3 in a 3 node cluster. We use rep

Re: Run Repairs when a Node is Down

node goes down). Issue https://issues.apache.org/jira/browse/CASSANDRA-10446 was created to allow repairing ranges with down replicas with a special flag (--force). If you're interested please add comments there and/or propose a patch. Thanks, Paulo 2016-01-17 1:33 GMT-03:00 Anuj Wadehra <anu

Run Repairs when a Node is Down

Hi  We are on 2.0.14,RF=3 in a 3 node cluster. We use repair -pr . Recently, we observed that repair -pr for all nodes fails if a node is down. Then I found the JIRA  https://issues.apache.org/jira/plugins/servlet/mobile#issue/CASSANDRA-2290 where an intentional decision was taken to abort the

Impact of Changing Compaction Strategy

Hi, I need to understand whether all existing sstables are recreated/updated when we change compaction strategy from STCS to DTCS? Sstables are immutable by design but do we take an exception for such cases and update same files when an Alter statement is fired to change the compaction

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