What would be the procedure for restoring snapshots of a Cassandra cluster to another cluster which has identical configuration? What are good reasons to create a city/nation in which a government wouldn't let you leave. API for Cassandra in Azure Cosmos DB has become a great choice for enterprise workloads running on Apache Cassandra for several reasons: No overhead of managing and monitoring: It eliminates the overhead of managing and monitoring settings across OS, JVM, and YAML files and their interactions. Review the basics of connecting to an Azure Cosmos DB for Apache Cassandra. Asking for help, clarification, or responding to other answers. Noise cancels but variance sums - contradiction? Solutions for migrating from other databases. Why is Bb8 better than Bc7 in this position? How to speed up hiding thousands of objects. Decommission the old cluster, as described in, Adding or removing nodes, datacenters, or clusters, Edge cases for transitioning or migrating a cluster, Adding a datacenter to a single-token architecture cluster, Replacing a dead node in a single-architecture cluster. General Inquiries: +1 (650) 389-6000 info@datastax.com, Is there a faster algorithm for max(ctz(x), ctz(y))? A few things to be careful about here: Be sure that the new cluster and the original cluster use the same Cassandra version and cluster name. Significant cost savings: You can save costs with the Azure Cosmos DB, which includes the cost of VMs, bandwidth, and any applicable licenses. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. As it turned out, Cassandra was the leading cause of such behavior since 500K+ of metrics had been being collected. In addition to covering the most popular programming languages today, we publish reviews and round-ups of developer tools that help devs reduce the time and money spent developing, maintaining, and debugging their applications. In order for this to work, your target cluster must have the same number of nodes, the same rack configuration, and even the same tokens assigned to each node. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Ensure that the table you are migrating to has at least 6,000 RUs available when you run the migration. For this, just run the following command in one of its pods: The total downtime of Cassandra lasted for about 3 minutes. nodes that are on the same data-center, rack, or EC2 regions.). Asking for help, clarification, or responding to other answers. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This article describes the steps required to migrate data from native Apache Cassandra keyspaces and tables into the Azure Cosmos DB for Apache Cassandra by using Azure Databricks. rev2023.6.2.43474. Review the supported features in the Azure Cosmos DB for Apache Cassandra to ensure compatibility. How strong is a strong tie splice to weight placed in it from above? If the LWT update failed because the second part failed, it means the update already succeeded in the past, and should no longer be retried. "::: You need to add the Apache Spark Cassandra Connector library to your cluster to connect to both native and Azure Cosmos DB Cassandra endpoints. Making statements based on opinion; back them up with references or personal experience. Can I also say: 'ich tut mir leid' instead of 'es tut mir leid'? It will not work for non-identical clusters because the partitions in the source SSTables will not necessarily fall in the token range(s) owned by the destination nodes. However, Cassandra is running on dedicated nodes. | Request units are divided equally among physical partitions, and heavy data skew can cause a bottleneck of requests to a single partition. Two methods for replacing a node with a new node, such as when updating to newer hardware or performing proactive maintenance. Depending on how the writes are done, code changes may be needed. For extra protection and peace of mind, the following technique also includes a rapid rollback strategy to return to your original configuration, up until the moment the migration is completed. Any other problem? What is the ideal way to merge two Cassandra clusters with same keyspace into one? Migrate data from Cassandra to an Azure Cosmos DB for Apache Cassandra This includes coverage of software management systems and project management (PM) software - all aimed at helping to shorten the software development lifecycle (SDL). Fabric is a complete analytics platform. Cannot retrieve contributors at this time. Join For Free Overview Data should be streamed to analytics engines in real-time or near real-time in order to. To get the tokens for a source node, you can run nodetool info -T | grep Token | awk '{print $3}' | tr '\n' , | sed 's/,$/\n/'. My Question is "What will happen if I move entire data_directory,Commit_log folder from production to local and start local cassandra?". Connect and share knowledge within a single location that is structured and easy to search. migration. IMPORTANT: Create the application keyspace on the destination cluster with the same replication settings as the source cluster. Did an AI-enabled drone attack the human operator in a simulation environment? We will create a temporary installation of Cassandra to solve this problem and use it as kind of a buffer to migrate data. STEP 1 - For the first table, create the schema on the destination cluster. Thanks for your inputs and it give me some insights. We recommend selecting Databricks runtime version 7.5, which supports Spark 3.0. :::image type="content" source="./media/migrate-data-databricks/databricks-runtime.png" alt-text="Screenshot that shows finding the Databricks runtime version. What one-octave set of notes is most comfortable for an SATB choir to sing in unison/octaves? Changing the strategy of a keyspace from SimpleStrategy to NetworkTopologyStrategy. However, if a significant skew is present in any other type of table, you might want to review your data model to avoid hot partition issues for your workload during steady-state operations. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. If necessary, allocate dedicated request units to that table. Transition a cluster on EC2 to a cluster on Amazon virtual private cloud Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. I have one production cassandra node and would like create same cassandra in my local machine. Not the answer you're looking for? Migrate data from cassandra to cassandra - Stack Overflow Can I also say: 'ich tut mir leid' instead of 'es tut mir leid'? How can an accidental cat scratch break skin but not damage clothes? Could entrained air be used to increase rocket efficiency, like a bypass fan? On a node in the old cluster, you would use the COPY TO: And then (after copying the file over) on a node in your new cluster, you would copy the data in the CSV file into Cassandra: Here is some more documentation on the COPY command. Caution! Does the grammatical context of 1 Chronicles 29:10 allow for it to be declaring that God is our Father? Why is Bb8 better than Bc7 in this position? when you have Vim mapped to always print two? Difference between partition key, composite key and clustering key in Cassandra? Migrating from MongoDB to Cassandra | FullContact Ability to use existing code and tools: The Azure Cosmos DB provides wire protocol-level compatibility with existing Cassandra SDKs and tools. Cassandra uses Bloom filters to determine whether an SSTable has data for a particular row. You can also add one more record to Cassandra-current to check that data replication is started: After that, you can ALTER all keyspaces in the Cassandra-current and run nodetool rebuild. Why wouldn't a plane start its take-off run from the very beginning of the runway to keep the option to utilize the full runway if necessary? I would think that you should also stop the production node if you just want to copy files otherwise it's going to change as you run your backup. The samples shown in this article have been tested with Spark version 3.0.1 and the corresponding Cassandra Spark Connector com.datastax.spark:spark-cassandra-connector-assembly_2.12:3.0.0. Connect and share knowledge within a single location that is structured and easy to search. This article describes the steps required to migrate data from native Apache Cassandra keyspaces and tables into the Azure . We had to configure routes for each pod on every node, which is a very time-consuming and, as a matter of fact, unreliable approach. Do you want all of the data replicated between the two clusters or only to reside on the second cluster? Steps for replacing nodes in single-token architecture clusters, not vnodes. How to migrate a cassandra counter table to another cluster? you may have to run nodetool repair afterward. About the COPY command How can I correctly use LazySubsets from Wolfram's Lazy package? STEP 1 - For the first table, create the schema on the destination cluster. The methods seen are as follows: It's really a question that requires more information to provide definitive answer. If it's 350 for the whole cluster, then definitely give COPY a try. What happens if you've already found the item an old map leads to? It appears that medusa can do this too though I have not used this tool before. The overall sequence of actions includes the following steps: Create the Cassandra-new cluster in the target Kubernetes cluster. Mount new volumes created by PVC to the old cluster. This would work but sounds inefficient and needs to address problems like "what to do if this script crashes in the middle of operation?". :::image type="content" source="./media/migrate-data-databricks/databricks-search-packages.png" alt-text="Screenshot that shows searching for Maven packages in Databricks. I had 350GB of data which will be faster? rev2023.6.2.43474. Even at minimum settings, Spark can write at a rate of around 6,000 request units or more. That is why we used the following command (execute it in each pod of Cassandra-current): It freed up some disk space: in our case, we got 500 GB of free disk space instead of 200 GB available before. Cassandra operation topics, such as node and datacenter operations, changing replication strategies, configuring compaction and compression, caching, and tuning Bloom filters. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. In this scenario, reduce to minimal throughput settings in Spark and force the migration to run slowly. Connect and share knowledge within a single location that is structured and easy to search. You can download the DataX toolkit on the official website. What do the characters on this CCTV lens mean? The benefits of this approach are: Minimal application changes. If necessary, allocate dedicated request units to that table. is to have in your LWT batch two statements for the same partition - one updating the actual counter in a static column, and the other one setting "unique id" clustering row on a client-generated unique id, if not yet set. Steps to replace a node that has died for some reason, such as hardware failure. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. Scale down Cassandra-temporary and Cassandra-current (keep in mind that the operator is still active in this cluster!) Two attempts of an if with an "and" are failing: if [ ] -a [ ] , if [[ && ]] Why? Follow this procedure to clone application data from a source cluster to the destination cluster in the example. Please, join our job satisfaction survey! This tutorial describes how to live migrate data to Azure Cosmos DB for Apache Cassandra from a native Apache Cassandra cluster using a dual-write proxy and Apache Spark. Using SSTABLELOADER: Most articles suggests using sstableloader to move data from one cluster to another. What happens if you've already found the item an old map leads to? Learn more about Stack Overflow the company, and our products. How can an accidental cat scratch break skin but not damage clothes? Is it possible to type a single quote/paren/etc. I think the best option is to use tools such as Apache Spark to read from source and write to target. However, despite the abundance of space, the rebuild operation has continually caused restarts of the Cassandra-temporary pods with the following message: We have solved this problem by defining a DaemonSet that rolls out to Cassandra-temporary nodes only and executes: Well, we finally got that migration sorted out! Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Once you have all of your target nodes set up with exactly the same tokens, DC, and racks as the source cluster, take a snapshot of the desired tables on the source cluster and copy the snapshots to the corresponding node's data directories on the target cluster. The dual-write proxy is used to capture live changes, while historical data is copied in bulk using Apache Spark. Ben Slater is Chief Product Officer at Instaclustr, a provider of enterprise-grade, hosted, and fully managed Apache Cassandra open source data infrastructure in the Cloud. Migrate data from Apache Cassandra to the Azure Cosmos DB for Apache Cassandra by using Databricks (Spark). To make changes, we would have had to clone the repository, modify source code, and rebuild the operator (good knowledge of Go is also a must since the config itself is built into the operator). Ensure you've already created empty keyspaces and tables in your target Azure Cosmos DB for Apache Cassandra account. ALTER all tables to remove the old cluster: 5. DataStax OpsCenter can automate the process of backing up and restoring data and will use direct copying for clusters with the same topology. that right I have single node cluster. Is it possible to design a compact antenna for detecting the presence of 50 Hz mains voltage at very short range? Excessive data skew with large data volume. We were able to successfully migrate the Cassandra database deployed in Kubernetes to another cluster while keeping the Cassandra production installation in a fully functioning state and without interfering with the operation of applications. How do I restore Cassandra snapshots to another cluster with identical Rationale for sending manned mission to another star? How to speed up hiding thousands of objects, Sound for when duct tape is being pulled off of a roll. It has all the necessary features, such as custom configurations and monitoring, right out-of-the-box. Set up and configure the new cluster as described in Initializing a cluster. Why? This tutorial provides instructions on different options available to migrate Apache Cassandra data into the API for Cassandra account in Azure Cosmos DB. However, our task was complicated by the fact that the networks in Kubernetes overlap, so it was difficult to establish a connection between clusters. This article describes the steps required to migrate data from native Apache Cassandra keyspaces and tables into the Azure Cosmos DB for Apache Cassandra by using Azure Databricks. Does Russia stamp passports of foreign tourists while entering or exiting Russia? | Why do some images depict the same constellations differently? From there you probably can debug issues. But, the fact is that if your application is able to remain online throughout connection setting changes, it can remain fully available during this transition. Further study revealed a 2.5-fold increase in the number of metrics collected! Find centralized, trusted content and collaborate around the technologies you use most. 1. First story of aliens pretending to be humans especially a "human" family (like Coneheads) that is trying to fit in, maybe for a long time? when you copy the snapshots to the new cluster in step 6. SELECT COUNT() returns ReadFailure after importing data from another cluster, Cassandra node fails to reconnect to the cluster on Kubernetes with Istio. Below is the code snippet from the reference links: http://www.russellspitzer.com/2016/02/16/Multiple-Clusters-SparkSql-Cassandra/, Transferring data from one cluster to another in Cassandra, For bulk data copy, you should think about sstableloader. Why? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Documentation for developers and administrators on installing, configuring, and using the features and capabilities of Apache Cassandra scalable open source NoSQL database. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Ensure that the table you are migrating to has at least 6,000 RUs available when you run the migration. To your local machine (assuming fresh install), Note: These checklists are not completely thorough. Not the answer you're looking for? Get Your Existing Environment Ready. K8ssandra is a cloud-native distribution of the Apache Cassandra database that runs on Kubernetes, with a suite of tools to ease and automate operational tasks. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Once you start the node, check its tokens using nodetool info -T to verify that it has the correct tokens. This compatibility ensures that you can use your existing codebase with the Azure Cosmos DB for Apache Cassandra with trivial changes. Azure Databricks is a platform as a service (PaaS) offering for Apache Spark that offers a way to perform offline migrations on a large scale. 8.45K Views Join the DZone community and get the full member experience. Then, update the replication settings in the new cluster to cease replication of data to the original cluster. Obviously, all these activities are very time-consuming. How to merge two Cassandra cluster into one? "::: Select Install, and then restart the cluster when installation is complete. 2 Based on what I have experienced, Spark is provides the best mechanism to do such activities. (VPC). One tool you could try would be the COPY TO/FROM cqlsh command. If you have provisioned a table in a keyspace with shared throughput, it's possible that this table has fewer than 6,000 RUs available at runtime. Scale down the Cassandra-new cluster to zero. How to do a Live Migration of a vanilla Cassandra cluster to a Datastax Enterprise Cluster, Migrate Datastax Enterprise Cassandra to Apache Cassandra, Datastax CE Cassandra migrate to Apache Cassandra, Migrate data from one cassandra cluster to another, Migration path from Datastax 6.0 to Cassandra 3, What are good reasons to create a city/nation in which a government wouldn't let you leave. This time was needed to stop and start containers only (since we prepared the disks beforehand). How is the entropy created for generating the mnemonic on the Jade hardware wallet? Then run the following code: [!NOTE] If the schema is different, you can specify how you want to map each column; so that's ok. Is the 350GB all one table? You must specify the same cluster name as in. Later versions of Spark and/or the Cassandra connector may not function as expected. to zero. Building a safer community: Announcing our new Code of Conduct, Balancing a PhD program with a startup career (Ep. How does one show in IPA that the first sound in "get" and "got" is different? For example, if the source keyspace is configured with a replication factor of 3 then the it needs to have RF=3 in the destination cluster as well. source and destination) are considered to have identical configuration when: If the conditions above are true, use the "refresh method" where SSTables from the nodes in the source cluster are copied to the corresponding nodes in the target cluster then "loaded" by running nodetool refresh. If however you did that, then something else is at work. Assuming you just want to recreate the production node on a local machine (as stated in the question), then it might be moot as the snapshot would have the current data. the future location. Create a Scala Notebook in Databricks. What is the replication? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA.