Angular – Progressive Web Apps using Service Workers Service workers enable creating progressive web applications. It is a script running in the web browser supporting caching of the application resources. They preserve the resources even after the user closes the tab and serves them when the application is requested again. Setting up Angular Project Let’s… Continue reading »
go – segmentation fault: 11 Running go after a few days, I notice that it is crashing with segmentation 11 error. In this post, we will try to get rid of this error in order to run go on our machine. Actually, I need this as a dependency to run some other development tool. Reading… Continue reading »
Hyperledger Fabric – Terminology Hyperledger Fabric is private and permissioned. In order to gain access, the peers need to be enrolled through a Membership Service Provider (MSP) . It has a deterministic consensus algorithm. Asset An asset holds a state and has ownership. They are key / value pairs representing a value, which enables to… Continue reading »
Hyperledger Fabric Composer & web sandbox Hyperledger Composer is an framework that allows development of Hyperledger fabric based blockchain applications. It must be noted that it has been deprecated with Fabric 1.4 released in August 2019. This is the first long term support release for Hyperledger fabric. It is pledged by maintainers to provide bug… Continue reading »
Apache Flink: could not find implicit value for evidence parameter of type This is a common error when transforming streams in Apache Flink based applications. The solution is simple. We just need to import the following: Which should import the necessary types for the operations.
Kafka Connect – Externalizing Secrets – KIP 297 In order to connect with a data source or sink, we need to use credentials. Kafka Connect added support for specifying credential using config providers. The support for file config provider is available with the installation package. This is discussed in KIP 297. The KIP was released… Continue reading »
Kafka Connect Couchbase Connector – Document Expiration Couchbase supports document expiration. If the documents are ingested from Kafka through Couchbase Sink connector the expiration can be set at the connector side where we can set the expiration for each record upserted as document in couchbase. Here is a sample configuration for the connector: Here is… Continue reading »
Securing JMX on Confluent Kafka Confluent kafka process start with these default arguments. You can see that JMX authentication is disabled by default. This is a security vulnerability and might lead to possible issues. Confluent kafka consists of the following services. We need to enable authentication for all of these services for JMX: Kafka Broker… Continue reading »
Kafka Tools – kafkacat – non-JVM Kafka producer / consumer kafkacat is an amazing kafka tool based on librdkafka library, which is a C/C++ library for kafka. It means that it doesn’t have dependency on JVM to work with kafka data as administrator. It can be used to consume and produce messages from kafka topics…. Continue reading »
Kafka Tools – kafka-delete-records While working with kafka we, sometimes, need to purge records from a topic. This is specially needed in a development environment where we just want to get rid of some records and want to keep the other ones. Previously we have discussed how we can purge all records from a topic… Continue reading »