Hazelcast is a distributed in-memory data grid, which allows to evenly share data among nodes in clustered environments. The open source version of Hazelcast does not support encryption at the transport or even at the cache level. So in order to secure traffic in the Hazelcast cluster, we need to extend it by making some […]
Docker and iptables firewall
Docker works perfectly fine when no firewall is running on the host machine. Without the firewall docker containers can communicate with each other and with the outside world. But with the firewall we need to setup some rules in order to allow traffic to and from the docker interface. Below it is detailed how we can […]
Atomic Updates on MongoDB with Spring Data
MongoDB provides operators for atomic updates in addition to the normal insert and modify functionality. These operators include, $inc, $set and $unset; and are particularly useful for keeping counters and for thread-safe field updates, which helps resolve data-related concurrency issues in web and multi-threaded applications. If persistence is required and performance is not an issue, these […]
CAS and distributed Infinispan integration
CAS is a centralised authentication server that makes it very easy to implement single sign-on (SSO) in java application, and is a very good OAuth alternative. For distributed/clustered environments CAS also offers integration with a number of caching technologies in order to support single-logout (SLO). Recently we had an issue on clustered Wildfly J2EE servers […]
Spring and Infinispan Integration on Wildfly Cluster
Spring framework provides a caching abstraction API that makes it very easy and consistent to use a lot of embeddable caching frameworks like, EHCache, Infinispan, Hazelcast etc. But sometimes it is also necessary to integrate with the underlying application server’s caching framework, especially in a clustered, distributed environment. In this post I will show how we can integrate […]
Spring Boot and WordPress CMS Integration
There are a lot of excellent open source content management systems available today, WordPress being one of them, which is widely used. WordPress is a PHP based CMS so not a lot of cohesion is available with other technologies like Java, and is simply ignored as a viable content management option just for being non-Java. In this […]
Using Standalone ActiveMQ Broker with Wildfly
Wildfly is an open source J2EE container, which comes with an embedded HornetQ JMS broker enabled by default in it’s full configuration. The embedded HornetQ works great out of the box, but sometimes it can be handy to use an existing JMS broker, like ActiveMQ. ActiveMQ includes a JCA resource adaptor that can be used […]
Protect your identity from SSH servers
Recently I came across a tweet that highlighted a serious privacy issue related to SSH servers and online services that publish user information in public domain without having to explicitly take permission from users. Added a OpenSSH roaming vuln test to the whoami server $ ssh https://t.co/MSn1TEQGTs (code: https://t.co/HMIH00CxHg) pic.twitter.com/9tolWWvXZJ — Filippo Valsorda (@FiloSottile) January […]
Real-time Web Cam Surveillance with Raspberry-PI
Raspberry PI is a great little tool for building small projects, from personal web servers to robot butlers. With it’s linux core you could potentially use RPI like a regular linux box. There are loads of example projects available on the internet. Here I will present how to use RPI to build a poor man’s […]
XMPP web chat with ejabberd, Converse.js and Spring MVC
Converse.js is a fine little XMPP web chat client that can easily be used in web applications. It can integrate with various online XMPP services, like Google Talk, MSN etc. In this post I will demonstrate how to use converse.js with ejabberd in a Spring based application. I used Ubuntu linux box to for this demo. […]
