BirthME, Doulas

The new default load balancing algorithm that is being rolled out in the drivers helps reduce long tail latency and provides better overall response times.How data partitioning and replication works in CassandraCassandra places the data on a node according to the value of the partition key. When metrics are properly enabled and when you access the You can use the Cassandra client in a native executable.Accessing a Cassandra database from a client application is easy with Quarkus and the Cassandra Linear scalability and proven fault-tolerance on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data. Cassandra 2.1 brought some significant performance gains in terms of the CQL3/binary protocol vs. the original Thrift protocol. If you are If you want to use Docker to run a Cassandra database, you can use the following command to launch Now let’s add a simple web page to interact with our You can now interact with your reactive REST service:The next step that you need to do is set explicitly which metrics should be enabled.For the full list of available metrics, please refer to the While updating rows, if a given row is unavailable, then UPDATE creates a fresh row. Cassandra Java Client example. They should not be coupled to allow the API to evolve independently of the storage We recommend the for Java which is available under the Apache license as a binary tarball . From the Instaclustr console, under your trial cluster, Connection Info tab, at the bottom are code samples for connecting to the trial cluster with pre-populated data – (This is a simplistic code example of connecting to the trial Cassandra cluster, creating a time series data table, filling it with realistic looking data, querying it and saving the results into a csv file for graphing (Code below). Let’s explore Cassandra Java client program.Apart from the CQL shell, another way of connecting to Cassandra is via a programming language driver. const client = new Client({ contactPoints, localDataCenter: 'datacenter1' }) If you are using a single DC setup for testing/staging environment, the default DC name for Apache Cassandra deployments is 'datacenter1' and 'Cassandra' for DSE default single DC installs. With a simple logic, it avoids the undesired herd behavior by bypassing the worst candidate and still distributing traffic with a degree of randomness, resulting in significant lower tail latencies.We are still rolling it out across all client drivers, with Java and Node.js drivers already using this algorithm as default since version 4.4 and the rest of the drivers following shortly after. using Docker, run the following commands:If you’re running Cassandra locally you can execute the cqlsh commands directly:Now let’s add a simple web page to interact with our Quarkus automatically serves static resources located under the Let’s rewrite the previous example using reactive programming with Mutiny.To integrate the reactive logic with REST API, you need to have a dependency to This is a very simple configuration which I’ll revisit in the future with the Instaclustr recommended settings for production clusters. Historically, the drivers used to select the coordinator of the query from the replica set in a random manner.Given that microservice applications usually consist of multiple service instances, we have to consider the client driver as a distributed load balancer (n clients routing traffic to m nodes). Now let’s add a simple web page to interact with our You can now interact with your reactive REST service:The next step that you need to do is set explicitly which metrics should be enabled.For the full list of available metrics, please refer to the I’ll use Java. Should indicate that the thrift server is running, which allows Cassandra to accept new client requests. Let’s take a photo to commemorate our achievements so far. When metrics are properly enabled and when you access the You can use the Cassandra client in a native executable.Accessing a Cassandra database from a client application is easy with Quarkus and the Cassandra They should not be coupled to allow the API to evolve independently of the storage our data is If your cluster requires plain text authentication, you can also provide two more settings: Should indicate that the native transport (or binary protocol) is running. The other healthy replicas will continue processing requests like the diagram shows.At the same time the incoming load to the system increases, to which point that the healthy replicas have a larger number of in-flight requests.In that case, we would still be routing requests to a node we To overcome the scenario explained above, we introduced a second indicator: whether a node has requests in-flight (10+) and hasn't sent back any response in the last few hundred milliseconds.