Re: compaction trigger after every fix interval

There's many things that can trigger a compaction, knowing the type of compaction can help narrow it down. Have you looked at the nodetool compactionstats command output when it is happening? What is the compaction type? It can be "compaction", but can also be something else, such as

Re: Trouble with using group commitlog_sync

, Apr 23, 2024 at 10:24 PM Bowen Song via user wrote: You might have run into the bottleneck of the driver's IO thread. Try increase the driver's connections-per-server limit to 2 or 3 if you've only got 1 server in the cluster. Or alternatively, run two client processes

Re: Mixed Cluster 4.0 and 4.1

having a schema mismatch for this long time. Should I be concerned, or have others upgraded in a similar way? Thanks Paul On 24 Apr 2024, at 17:02, Bowen Song via user wrote: Hi Paul, You don't need to plan for or introduce an outage for a rolling upgrade, which is the preferred route

Re: Mixed Cluster 4.0 and 4.1

Hi Paul, You don't need to plan for or introduce an outage for a rolling upgrade, which is the preferred route. It isn't advisable to take down an entire DC to do upgrade. You should aim to complete upgrading the entire cluster and finish a full repair within the shortest gc_grace_seconds

Re: Trouble with using group commitlog_sync

:46 PM Bowen Song via user wrote: To achieve 10k loop iterations per second, each iteration must take 0.1 milliseconds or less. Considering that each iteration needs to lock and unlock the semaphore (two syscalls) and make network requests (more syscalls), that's a lots

Re: Trouble with using group commitlog_sync

, I do see 100% CPU utilization in every single one of these tests. On Tue, Apr 23, 2024 at 11:01 AM Bowen Song via user wrote: Have you checked the thread CPU utilisation of the client side? You likely will need more than one thread to do insertion in a loop to achieve tens

Re: Trouble with using group commitlog_sync

23, 2024 at 10:45 AM Bowen Song via user wrote: I suspect you are abusing batch statements. Batch statements should only be used where atomicity or isolation is needed. Using batch statements won't make inserting multiple partitions faster. In fact, it often will make that slower

Re: Trouble with using group commitlog_sync

If I set commitlog_sync_group_window to 1ms, the throughput increases to 13k / second, which is slightly less than batch commit mode. Is group commit mode supposed to have better performance than batch mode? On Tue, Apr 23, 2024 at 8:46 AM Bowen Song via user wrote: T

Re: Trouble with using group commitlog_sync

o the default 1000ms. On Tue, Apr 23, 2024 at 8:15 AM Bowen Song via user wrote: Why would you want to set commitlog_sync_batch_window to 1 second long when commitlog_sync is set to batch mode? The documentation <https://cassandra.apache.org/doc/stable/cassandra/architecture/stor

Re: Trouble with using group commitlog_sync

Why would you want to set commitlog_sync_batch_window to 1 second long when commitlog_sync is set to batch mode? The documentation on this says: /This window should be kept short because the writer threads

Re: Alternate apt repo for Debian installation?

You can try https://archive.apache.org/dist/cassandra/debian/ The deb files can be found here: https://archive.apache.org/dist/cassandra/debian/pool/main/c/cassandra/ On 20/03/2024 20:47, Grant Talarico wrote: Hi there. Hopefully this is the right place to ask this question. I'm trying to

Re: [EXTERNAL] Re: About Cassandra stable version having Java 17 support

you please let us know when the team is planning to GA Cassandra 5.0 version which has Java 17 support? Regards, Divyanshi *From:* Bowen Song via user *Sent:* Monday, March 18, 2024 5:14 PM *To:* user@cassandra.apache.org

Re: About Cassandra stable version having Java 17 support

Why Java 17? It makes no sense to choose an officially non-supported library version for a piece of software. That decision making process is the problem, not the software's library version compatibility. On 18/03/2024 09:44, Divyanshi Kaushik via user wrote: Hi All, As per my project

Re: Best Practices for Managing Concurrent Client Connections in Cassandra

They are suitable for production use for protecting your Cassandra server, not the clients. The clients likely will experience an error when the limit is reached, and it needs to handle that error appropriately. What you really want to do probably are: 1. change the client's behaviour, limit

Re: Cassandra 4.1 compaction thread no longer low priority (cpu nice)

commit/f382fb0bcef4c37dc049e9f6963e3baf204d815c). Regards, Dmitry On Thu, 22 Feb 2024 at 15:30, Bowen Song via user wrote: Hi Pierre, Is there anything stopping you from using the compaction_throughput <https://github.com/apache/cassandra/blob/f9e033f519c14596da4dc954875756a69aea4e78/conf/cassandra.

Re: Cassandra 4.1 compaction thread no longer low priority (cpu nice)

Hi Pierre, Is there anything stopping you from using the compaction_throughput option in the cassandra.yaml file to manage the performance impact of compaction operations? With

Re: Requesting Feedback for Cassandra as a backup solution.

duce those to the respective topic when Kafka is live. Thanks and regards, Gowtham S On Sat, 17 Feb 2024 at 18:10, Bowen Song via user wrote: Hi Gowtham, On the face of it, it sounds like you are planning to use Cassandra for a queue-like application, which is a well documente

Re: Requesting Feedback for Cassandra as a backup solution.

Hi Gowtham, On the face of it, it sounds like you are planning to use Cassandra for a queue-like application, which is a well documented anti-pattern. If that's not the case, can you please show the table schema and some example queries? Cheers, Bowen On 17/02/2024 08:44, Gowtham S wrote:

Re: Switching to Incremental Repair

, we have nodes where the disk usage is multiple TiBs so significant growth can be quite dangerous in our case. Would the only safe choice be to mark all SSTables as unrepaired before stopping regular incremental repair? Thanks, Kristijonas On Wed, Feb 7, 2024 at 4:33 PM Bowen Song via user

Re: Switching to Incremental Repair

schrieb Bowen Song via user : Unfortunately repair doesn't compare each partition individually. Instead, it groups multiple partitions together and calculate a hash of them, stores the hash in a leaf of a merkle tree, and then compares the merkle trees between replicas during a repair session

Re: Switching to Incremental Repair

Unfortunately repair doesn't compare each partition individually. Instead, it groups multiple partitions together and calculate a hash of them, stores the hash in a leaf of a merkle tree, and then compares the merkle trees between replicas during a repair session. If any one of the partitions

Re: Switching to Incremental Repair

Caution, using the method you described, the amount of data streamed at the end with the full repair is not the amount of data written between stopping the first node and the last node, but depends on the table size, the number of partitions written, their distribution in the ring and the

Re: Switching to Incremental Repair

Just one more thing. Make sure you run 'nodetool repair -full' instead of just 'nodetool repair'. That's because the command's default was changed in Cassandra 2.x. The default was full repair before that change, but the new default now is incremental repair. On 07/02/2024 10:28, Bowen Song

Re: Switching to Incremental Repair

Not disabling auto-compaction may result in repaired SSTables getting compacted together with unrepaired SSTables before the repair state is set on them, which leads to mismatch in the repaired data between nodes, and potentially very expensive over-streaming in a future full repair. You

Re: Switching to Incremental Repair

Full repair running for an entire week sounds excessively long. Even if you've got 1 TB of data per node, 1 week means the repair speed is less than 2 MB/s, that's very slow. Perhaps you should focus on finding the bottleneck of the full repair speed and work on that instead. On 03/02/2024

Re: Switching to Incremental Repair

condition? Thanks, Kristijonas On Fri, Feb 2, 2024 at 3:36 PM Bowen Song via user wrote: Hi Kristijonas, To answer your questions: 1. It's still necessary to run full repair on a cluster on which incremental repair is run periodically. The frequency of full repair is more

Re: Switching to Incremental Repair

Hi Kristijonas, To answer your questions: 1. It's still necessary to run full repair on a cluster on which incremental repair is run periodically. The frequency of full repair is more of an art than science. Generally speaking, the less reliable the storage media, the more frequently full

Re: Tests failing for ppc64le architecture.

Hi Sunidhi, In case you haven't noticed, this is the Cassandra user mailing list, not the dev mailing list. Most people in this mailing list have never attempted to built Cassandra from the source code. IMHO you should try the Cassandra dev mailing list for this type of things. Cheers,

Re: Over streaming in one node during repair.

Some common causes of over-streaming: * "repair_session_space" is too small (either manually specified, or heap size is small and data on disk is large) * Manually deleting SSTable files * Unexpected foreign (e.g. from a backup) SSTable files * Marking SSTable as repaired or unrepaired

Re: COMMERCIAL:Re: COMMERCIAL:Re: COMMERCIAL:Re: system_schema.tables id and table uuid on disk mismatch

. removing the incorrect directory afterwards *From:* Bowen Song via user *Sent:* Thursday, January 18, 2024 5:34:57 PM *To:* user@cassandra.apache.org *Cc:* Bowen Song *Subject:* COMMERCIAL:Re: COMMERCIAL:Re: COMMERCIAL:Re

Re: COMMERCIAL:Re: COMMERCIAL:Re: system_schema.tables id and table uuid on disk mismatch

: It has same mismatch id in all nodes not just one node. *From:* Bowen Song via user *Sent:* Thursday, January 18, 2024 3:18:11 PM *To:* user@cassandra.apache.org *Cc:* Bowen Song *Subject:* COMMERCIAL:Re: COMMERCIAL:Re

Re: COMMERCIAL:Re: system_schema.tables id and table uuid on disk mismatch

data before nodetool import. Thanks again. *From:* Bowen Song via user *Sent:* Thursday, January 18, 2024 1:17:11 PM *To:* user@cassandra.apache.org *Cc:* Bowen Song *Subject:* COMMERCIAL:Re: system_schema.tables id

Re: system_schema.tables id and table uuid on disk mismatch

It sounds like you have done some concurrent table creation/deletion in the past (e.g. CREATE TABLE IF NOT EXISTS from multiple clients), which resulted in this mismatch. After you restarted the node, Cassandra corrected it by discarding the old table ID and any data associated with it. This

Re: About Map column

Hi Sebastien, It's a bit more complicated than that. To begin with, the first-class citizen in Cassandra is partition, not row. All map fields in the same row are in the same partition, and all rows with the same partition key but different clustering keys are also in the same partition.

Re: Schema inconsistency in mixed-version cluster

I don't recognise those names: * channel_data_id * control_system_type * server_id * decimation_levels I assume these are column names of a non-system table. From the stack trace, this looks like an error from a node which was running 4.1.3, and this node was not the coordinator for this

Re: Remove folders of deleted tables

1st use case, and then perform a small number of queries to merge pre-results client-side) and in that case TTL+TWCS would probably apply, it remains the same question as above. Thanks for your time :) Sébastien. Le mer. 6 déc. 2023 à 15:46, Bowen Song via user a écrit : There ar

Re: Remove folders of deleted tables

nfirm (or invalidate) that please? Sébastien. Le mer. 6 déc. 2023 à 03:00, Bowen Song via user a écrit : The same table name with two different CF IDs is not just "temporary schema disagreements", it's much worse than that. This breaks the eventual consistency guarantee, and leads

Re: Remove folders of deleted tables

er has 65K subfolders, so I would say I have time to think of redesigning the data model ^^ Nevertheless, does it sound too much in terms of thombstones in the systems tables (with the default GC grace period of 10 days)? Sébastien. Le mar. 5 déc. 2023, 12:19, Bowen Song via user a écrit :

Re: Remove folders of deleted tables

Please rethink your use case. Create and delete tables concurrently often lead to schema disagreement. Even doing so on a single node sequentially will lead to a large number of tombstones in the system tables. On 04/12/2023 19:55, Sébastien Rebecchi wrote: Thank you Dipan. Do you know if

Re: Migrating to incremental repair in C* 4.x

Hi Jeff, Does subrange repair mark the SSTable as repaired? From my memory, it doesn't. Regards, Bowen On 27/11/2023 16:47, Jeff Jirsa wrote: I don’t work for datastax, thats not my blog, and I’m on a phone and potentially missing nuance, but I’d never try to convert a cluster to IR by

Re: Memory and caches

Hi Sebastien, What's your goal? Improving cache hit rate purely for the sake of having a higher hit rate is rarely a good goal, because higher cache hit rate doesn't always mean faster operations. Do you have specific issues with performance? If so, can you please tell us more about it?

Re: Migrating to incremental repair in C* 4.x

Hi Sebastian, It's better to walk down the path on which others have walked before you and had great success, than a path that nobody has ever walked. For the former, you know it's relatively safe and it works. The same can hardly be said for the later. You said it takes a week to run the

Re: Cassandra stopped responding but still alive

What do you mean by saying "Cassandra stopped responding ... to nodetool requests"? Is it a specific nodetool command (e.g. "nodetool status") or all nodetool commands? What's the issue? Was it an error message, such as connection refused? Or freezes/unresponsive? It's common to see Cassandra

Re: java driver with cassandra proxies (option: -Dcassandra.join_ring=false)

I'm not 100% sure, but it's worth trying to disable the token metadata , because the driver needs to read the "system.peers_v2" table for populating the token metadata. On 11/10/2023 19:15,

Re: [HELP] Cassandra 4.1.1 Repeated Bootstrapping Failure

ed in 4.1.1. On Sep 11, 2023, at 2:09 PM, Bowen Song via user wrote: *Description* When adding a new node to an existing cluster, the new node bootstrapping fails with the "io.netty.channel.unix.Errors$NativeIoException: writeAddress(..) failed: Connection timed out" e

[HELP] Cassandra 4.1.1 Repeated Bootstrapping Failure

*Description* When adding a new node to an existing cluster, the new node bootstrapping fails with the "io.netty.channel.unix.Errors$NativeIoException: writeAddress(..) failed: Connection timed out" error from the streaming source node. Resuming the bootstrap with "nodetool bootstrap

Re: Big Data Question

, but the repairs are painful.  I come from the Hadoop world where it was all about large servers with lots of disk. Relatively small number of tables, but some have a high number of rows, 10bil + - we use spark to run across all the data. -Joe On 8/17/2023 12:13 PM, Bowen Song via user wrote

Re: Big Data Question

delle* *email: daeme...@gmail.com* *LI: https://www.linkedin.com/in/daemeonreiydelle/* *San Francisco 1.415.501.0198/Skype daemeon.c.m.reiydelle* On Thu, Aug 17, 2023 at 6:13 AM Bowen Song via user wrote: Just pointing out the obvious, for 1PB of data on nodes with 2TB disk each, you wil

Re: Big Data Question

, but you'd have to run 40 instances of Cassandra on each server; maybe 24G of heap per instance, so a server with 1TByte of RAM would work. Is this what folks would do? -Joe On 8/17/2023 9:13 AM, Bowen Song via user wrote: Just pointing out the obvious, for 1PB of data on nodes with 2TB disk each

Re: Big Data Question

Just pointing out the obvious, for 1PB of data on nodes with 2TB disk each, you will need far more than 500 nodes. 1, it is unwise to run Cassandra with replication factor 1. It usually makes sense to use RF=3, so 1PB data will cost 3PB of storage space, minimal of 1500 such nodes. 2,

Re: 2 nodes marked as '?N' in 5 node cluster

The first thing to look is the logs, specifically, the /var/log/cassandra/system.log file on each node. 5 seconds time drift is enough to cause Cassandra to fail. You should ensure the time difference between Cassandra nodes is very low by ensure time sync is working correctly, otherwise

Re: Survey about the parsing of the tooling's output

We parse the output of the following nodetool sub-commands in our custom scripts: * status * netstats * tpstats * ring We don't mind the output format change between major releases as long as all the following are true: 1. major releases are not too frequent e.g. no more frequent

Re: 4.0 upgrade

You should not make DDL (e.g. TRUNCATE, ALTER TABLE) or DCL (e.g. GRANT, ALTER ROLE) operations or run repair on a mixed version cluster. Source: https://www.datastax.com/learn/whats-new-for-cassandra-4/migrating-cassandra-4x You should also ensure the gc_grace_seconds value is large enough to

Re: Upgrade from 3.11.5 to 4.1.x

Assuming "do it in one go" means a rolling upgrade from 3.11.5 to 4.1.2 skipping all version numbers between these two, the answer is yes, you can "do it in one go". On 08/07/2023 01:14, Surbhi Gupta wrote: Hi, We have to upgrade from 3.11.5 to 4.1.x . Can we do it in one go ? Or do we have

Re: Issue while node addition on cassandra 4.0.7

29/06/2023 12:42, Bowen Song wrote: Did anyone connecting to the servers' storage port via telnet, nc (netcat) or something similar? 218762506 is 0x0D0A0D0A, which is two newlines. On 29/06/2023 11:49, MyWorld wrote: When checked in the source nodes, we got similar errors. Forgot to mention, w

Re: Issue while node addition on cassandra 4.0.7

essage$InvalidLegacyProtocolMagic: Read 218762506, Expected -900387334 On Thu, Jun 29, 2023 at 2:57 PM Bowen Song via user wrote: The expected value "-900387334" is the little endian decimal representation of the PROTOCOL_MAGIC value 0xCA552DFA defined in the net/Message.java <

Re: Issue while node addition on cassandra 4.0.7

The expected value "-900387334" is the little endian decimal representation of the PROTOCOL_MAGIC value 0xCA552DFA defined in the net/Message.java file. The

Re: Impact of column names on storage

Actually, I was wrong. The column names are not stored in the *-Data.db files, but stored in the *-Statistics.db files. Cassandra only stores one copy of the column names per SSTable data file, therefore the disk space usage is negligible. On 12/06/2023 14:31, Bowen Song wrote: The SSTable

Re: Impact of column names on storage

The SSTable compression will take care of the storage space usage, which means users usually don't need to worry about the length of column names, unless they are ridiculously long and hard to compress, or if SSTable compression is turned off. On 12/06/2023 13:55, Dimpal Gurabani wrote: Hi

Re: Is cleanup is required if cluster topology changes

d, and see how it goes. We will keep you updated on our progress. Thanks a lot once again! Jaydeep On Fri, May 5, 2023 at 8:55 AM Bowen Song via user wrote: Depending on the number of vnodes

Re: Is cleanup is required if cluster topology changes

wn during the node replacement period, we will get availability drop because most of our use case is local_quorum with replication factor 3. On Fri, May 5, 2023 at 5:59 AM Bowen Song via user wrote: Have you thought of using "-Dcassandra.replace_address_first_boot=..." (or

Re: Is cleanup is required if cluster topology changes

Have you thought of using "-Dcassandra.replace_address_first_boot=..." (or "-Dcassandra.replace_address=..." if you are using an older version)? This will not result in a topology change, which means "nodetool cleanup" is not needed after the operation is completed. On 05/05/2023 05:24,

Re: Optimization for partitions with high number of rows

ern in this table is such that all data for a given row is written at the same time, so I know I can use frozen udt instead of this, making it faster, but I wonder if there is another way. On Tue, Apr 11, 2023 at 9:06 PM Bowen Song via user wrote: Reading 4MB from 70k rows and 13 columns (0

Re: Optimization for partitions with high number of rows

Reading 4MB from 70k rows and 13 columns (0.91 million cells) from disk in 120ms doesn't sound bad. That's a lots of deserialisation to do. If you want it to be faster, you can store the number of rows elsewhere if that's the only thing you need. On 11/04/2023 07:13, Gil Ganz wrote: Hey I

Re: CAS operation result is unknown - proposal accepted by 1 but not a quorum

That error message sounds like one of the nodes timed out in the paxos propose stage.  You can check the system.log and gc.log and see if you can find anything unusual in them, such as network errors, out of sync clocks or long stop-the-world GC pauses. BTW, since you said you want it to be

Re: Issues during Install/Remove Cassandra ver 4.0.x

Since you have already downloaded the RPM file, you may install it with "yum install cassandra-4.0.7-1.noarch.rpm" command. This will install the package with all of its dependencies. BTW, you can even run "yum install https://redhat.cassandra.apache.org/40x/cassandra-4.0.7-1.noarch.rpm; to

Re: Reads not returning data after adding node

. On 05/04/2023 05:24, David Tinker wrote: The Datastax doc says to run cleanup one node at a time after bootstrapping has completed. The myadventuresincoding post says to run a repair on each node first. Is it necessary to run the repairs first? Thanks. On Tue, Apr 4, 2023 at 1:11 PM Bowen Song via

Re: When are sstables that were compacted deleted?

It may be useful to attach the output from the nodetool tpstats, nodetool compactionstats and nodetool netstats commands output. If any SSTable involved in a transaction is being compacted, repaired or streamed, etc., the transaction clean up will be delayed. This is the expected behaviour.

Re: Reads not returning data after adding node

%  ab72f017-be96-41d2-9bef-a551dec2c7b5  rack1 On Mon, Apr 3, 2023 at 5:42 PM Bowen Song via user wrote: That's correct. nodetool removenode is strongly preferred when your node is already down. If the node is still functional, use nodetool decommission on the node

Re: Reads not returning data after adding node

` is designed to be run when a host is offline. Only decommission is guaranteed to maintain consistency / correctness, and removemode probably streams a lot more data around than decommission. On Mon, Apr 3, 2023 at 6:47 AM Bowen Song via user wrote: Use nodetool removenode is strongly preferred

Re: Understanding rack in cassandra-rackdc.properties

I just want to mention that the "rack" in Cassandra don't need to match the physical rack. As long as each "rack" in Cassandra fails independent of each other, it is fine. That means if you have 6 physical servers each in an unique physical rack and Cassandra RF=3, you can have any of the

Re: Reads not returning data after adding node

Use nodetool removenode is strongly preferred in most circumstances, and only resort to assassinate if you do not care about data consistency or you know there won't be any consistency issue (e.g. no new writes and did not run nodetool cleanup). Since the size of data on the new node is

Re: Nodetool command to pre-load the chunk cache

It sounds like a bad policy, and you should push for that to be changed. Failing that, you have some options: 1. Use faster disks. This improves cold start performance, without relying on the caches. 2. Rely on row cache instead. It can be saved periodically and loaded at startup time. 3.

Re: New DC / token distribution not balanced

Lab <http://www.dsimb.inserm.fr/> <https://www.energylab.re> Interne : 2357 | Externe : +262 262 93 86 08 . <http://www.univ-reunion.fr/> Le jeu. 16 mars 2023 à 21:02, Bowen Song via user a écrit : No, allocate_tokens_for_local_replication_factor does not exist in Cassandra 3. It

Re: New DC / token distribution not balanced

No, allocate_tokens_for_local_replication_factor does not exist in Cassandra 3. It was introduced in Cassandra 4.0. Now, may I interest you with an upgrade? Not only Cassandra 4 comes with a lots of improvements and bug fixes, it's also a fairly painless process. I find it much easier to

Re: New DC / token distribution not balanced

You may find "allocate_tokens_for_local_replication_factor" more useful than "allocate_tokens_for_keyspace" when you are spinning up a new DC. On 16/03/2023 06:25, Max Campos wrote: Update:  I figured out the problem! The “allocate_tokens_for_keyspace” value needs to be set for a keyspace

Re: Adding an IPv6-only server to a dual-stack cluster

as broadcast_address reports the same single IPv4 address that the node always reported previously? The presence of broadcast_address removes the "different nodes in the cluster pick different addresses for you" case? On 2022-11-16 14:03, Bowen Song via user wrote: I would expect that y

Re: Adding an IPv6-only server to a dual-stack cluster

I would expect that you'll need NAT64 in order to have a cluster with mixed nodes between IPv6-only servers and dual-stack servers that's broadcasting their IPv4 addresses. Once all IPv4-broadcasting dual-stack nodes are replaced with nodes either IPv6-only or dual-stack but broadcasting IPv6

Re: Query drivertimeout PT2S

This is a mailing list for the Apache Cassandra, and that's not the same as DataStax Enterprise Cassandra you are using. We may still be able to help here if you could provide more details, such as the queries, table schema, system stats (cpu, ram, disk io, network, and so on), logs, table

Re: Upgrade

You should take a snapshot before starting the upgrade process. You cannot achieve a snapshot of "the most current situation" in a live cluster anyway, as data are constantly written to the cluster even after a node is stopped for upgrading. So you've gotta to accept the outdated snapshots if

Re: Upgrade Pt2

Please read https://docs.datastax.com/en/upgrading/docs/datastax_enterprise/upgrdCstarToDSE.html#_general_restrictions The document is written for DSE Cassandra, but must of it applies to Apache Cassandra too. In short, watch out for these: Client side: * Check client driver

Re: Questions on the count and multiple index behaviour in cassandra

It sounds like you are misusing/abusing Cassandra. I've noticed the following Cassandra anti-patterns in your post: 1. Large or uneven partitions All rows in a table in a single partition is definitely an anti-pattern unless you only have a very small number of rows. 2. "SELECT COUNT(*)

Re: node decommission

No, decommission does not decrease the load, as it only streams the data to other nodes, but doesn't remove them locally. However, decommission also shouldn't increase the load either. I can't offer an explanation for the load increase in your case. On 26/09/2022 15:03, Marc Hoppins wrote:

Re: Cassandra data sync time

available between the DCs), the streaming process itself should only take minutes. On 26/09/2022 12:14, Kaushal Shriyan wrote: On Fri, Sep 23, 2022 at 8:39 PM Bowen Song via user wrote: What's your definition of "sync"? Streaming all the existing data to the new DC? or th

Re: Cassandra data sync time

What's your definition of "sync"? Streaming all the existing data to the new DC? or the time lag between a write request is completed in one DC and the other DC? The former can be estimated based on a few facts about your setup (number of nodes, data size, etc.) and some measured data

Re: Restart Cassandra

mit directory. -Original Message- From: Bowen Song via user Sent: Friday, September 23, 2022 3:47 PM To: user@cassandra.apache.org Subject: Re: Restart Cassandra EXTERNAL Did the node finish starting when you checked the "nodetool status" output? Try "nodetool netstats" on the st

Re: Restart Cassandra

Did the node finish starting when you checked the "nodetool status" output? Try "nodetool netstats" on the starting node, the output will show "Mode: NORMAL" if it has finished starting. It's also worth checking the "nodetool info" output, and make sure "Gossip active" and "Native Transport

Re: Understanding multi region read query and latency

PM Stéphane Alleaume wrote: You're right too, this option is not new, sorry. Is this option can be useful ? Le dim. 7 août 2022, 22:18, Bowen Song via user a écrit : Do you mean "nodetool settraceprobability"? This is not exactly new, I remember it

Re: Understanding multi region read query and latency

f request I got approximately 98% of request treated in 2/3ms in local DC with one read request, and 2% treated by many nodes (according to the trace) and then way longer (250ms). ? On 06/08/2022 14:30, Bowen Song via user wrote: See the diagram below. Your problem

Exception encountered during startup: TruncateException

Hello, I have Cassandra 4.0.1 on a server failing to start. The server was power cycled after it experienced an unrecoverable memory error detected by EDAC. The memory error was transitory, and AFAIK it has disappeared. But Cassandra is not starting. The logs are: INFO  [main]

Re: Understanding multi region read query and latency

The  DCAwareRoundRobinPolicy/TokenAwareHostPolicy controlls which Cassandra coordinator node the client sends queries to, not the nodes it connects to, nor the nodes that performs the actual read. A client sends a CQL read query to a coordinator node, and the coordinator node parses the CQL

Re: unsubscribe

Please send an email to "user-unsubscr...@cassandra.apache.org" to unsubscribe from this mailing list. On 04/08/2022 18:29, Dathan Vance Pattishall wrote: unsubscribe

Re: Service shutdown

Generally speaking, I've seen Cassandra process stopping for the following reasons: OOM killer JVM OOM Received a signal, such as SIGTERM and SIGKILL File IO error when disk_failure_policy or commit_failure_policy is set to die Hardware issues, such as memory corruption,

Re: Wrong Consistency level seems to be used

It doesn't make any sense to see consistency level ALL if the code is not explicitly using it. My best guess is somewhere in the code the consistency level was overridden. On 21/07/2022 14:52, pwozniak wrote: Hi, we have the following code (java driver): cluster

Re: Adding nodes

To unsubscribe, please send an email to user-unsubscr...@cassandra.apache.org On 20/07/2022 18:34, emmanuel warreng wrote: Unsubscribe On Thu, Jul 7, 2022, 16:49 Marc Hoppins wrote: Hi all, Cluster of 2 DC and 24 nodes DC1 (RF3) = 12 nodes, 16 tokens each DC2 (RF3) = 12

Re: Adding nodes

to suggest that folk head off a pay for a course when there are ‘pre-sales’ questions is not a practical response as any business is unlikely to be spending speculative money. *From:*Jeff Jirsa *Sent:* Tuesday, July 12, 2022 4:43 PM *To:* cassandra *Cc:* Bowen Song *Subject:* Re: Adding nodes

Re: Adding nodes

 or whatever, it is a serious limitation as not every business/organisation is going to have multiple racks available. *From:*Bowen Song via user *Sent:* Monday, July 11, 2022 8:57 PM *To:* user@cassandra.apache.org *Subject:* Re: Adding nodes EXTERNAL I've noticed the joining node has a different

Re: Adding nodes

times. -Joe On 7/11/2022 6:23 AM, Bowen Song via user wrote: You should look for warning and error level logs in the system.log, not the debug.log or gc.log, and certainly not only the latest lines. BTW, you may want to spend some time investigating potential GC issues based

Re: Adding nodes

al=0.03 secs] *From:*Bowen Song via user *Sent:* Monday, July 11, 2022 11:56 AM *To:* user@cassandra.apache.org *Subject:* Re: Adding nodes EXTERNAL Checking on multiple nodes won't help if the joining node suffers from any of the issues I described, as it will likely be flipping up and dow

Re: Adding nodes

. Therefore, if I know when my first node is finished, I will have an idea of how long before I check for the when subsequent nodes can be joined. *From:*Bowen Song via user *Sent:* Monday, July 11, 2022 11:25 AM *To:* user@cassandra.apache.org *Subject:* Re: Adding nodes EXTERNAL Sleeping/pausing

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