Author: Neha Bhardwaj

Couchbase Java SDK Tutorial – CRUD Operations

In this blog, we will learn to implement CRUD operations in Couchbase with a Java application. So, let’s begin with a quick introduction of the Couchbase Server. Introduction to Couchbase Couchbase Server is an open source, distributed, NoSQL document-oriented engagement database with many advantages over traditional RDBMS like:- Fast key-value store with managed cache for sub-millisecond data operations. Purpose-built indexers for fast queries. A powerful Continue Reading

Error Registering Avro Schema | Multiple Schemas In One Topic

org.apache.kafka.common.errors.SerializationException: Error registering Avro schema: {“type”:”record”,”name”:”schema1″,”namespace”:”test”,”fields”:[{“name”:”Name”,”type”:”string”},{“name”:”Age”,”type”:”int”},{“name”:”Location”,”type”:”string”}]} Caused by: io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException: Schema being registered is incompatible with an earlier schema; error code: 409 at io.confluent.kafka.schemaregistry.client.rest.RestService.sendHttpRequest(RestService.java:170) at io.confluent.kafka.schemaregistry.client.rest.RestService.httpRequest(RestService.java:188) at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:245) at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:237) at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:232) at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.registerAndGetId(CachedSchemaRegistryClient.java:59) at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.register(CachedSchemaRegistryClient.java:91) at io.confluent.kafka.serializers.AbstractKafkaAvroSerializer.serializeImpl(AbstractKafkaAvroSerializer.java:72) at io.confluent.kafka.formatter.AvroMessageReader.readMessage(AvroMessageReader.java:158) at kafka.tools.ConsoleProducer$.main(ConsoleProducer.scala:57) at kafka.tools.ConsoleProducer.main(ConsoleProducer.scala) You might have come across a similar exception while working with AVRO schemas. Kafka throws this exception due to a compatibility issue Continue Reading

Transforming to a New World with Blockchain Technology

The Blockchain technology is booming beyond belief. But apart from the definition or relating it to BITCOINS what else do we know about The Blockchain? Reading articles regarding this, all I could summarize about Blockchain is that it is a- Distributed and immutable (write once and read only) Database/System. A public ledger of all distributed transactions. Key features include Security, Integrity, Accessibility. A well-known implementation Continue Reading

Partitioning in Database

To speed up the query processing, we need to efficiently manage data. And partitioning the database is considered as one of the ways to enhance the processing speed. Using Partitioning, we can divide the data based on some value/field, so that data belonging to different groups are identified easily(may be stored on different nodes), and therefore processing a query won’t require a Full Table Scan, Continue Reading

Understanding Lightbend Telemetry

Let’s begin by understanding each of its meaning. Lightbend(formerly known as ‘Typesafe’) provides an open-source platform for building Reactive applications for the JVM, consisting of the Play Framework, Akka middleware and Scala programming language. And, Telemetry = tele(remote) + metron(measure) Lightbend Telemetry provides insight into applications built with Lightbend technologies. Some of the Lightbend technologies are mentioned below : Akka  Apache Cassandra  Apache Kafka  Apache Continue Reading

What makes CockroachDB Unique !!

In my blog today, I will be comparing CockroachDB with the existing databases like MySQL, Oracle, Cassandra, HBase and so on.. Let’s have a look at what makes CockroachDB different from other databases. Referring the following table we can compare different databases against each other depending on their features. As we can see, most of the features are present in CockroachDB, but the main concern Continue Reading

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