In order to use kafka in a Java we need to get the kafka-client library from the maven repository (maven or gradle can be used)
- Kafka allows us to decouple data-streams and applications
- Created by Linkedln, now Open Source project and maintainted by Confluent
One should be careful when using AWS lambda with environment variables. If you don’t pay attention you may end-up wondering why your function is not working as expected. I personally had an issue of using PATH variable, if say it more exactly
process.environment.PATH with runtime: Node.js 12.x. Because in version Node.js 10.x you won’t face this problem.
When AWS ElasticBeanstalk informs about upcoming platform upgrades, we must take it seriously and prepare our CI scripts. Because when I first time saw the warning that says “Platform update scheduled”, didn’t pay much attention. When clicked for details it said:
In this blog I have collected some knowledges about OrientDB which is multi-model graph database. This blog can be referred to to some kind of fact checks about OrientDB.
- Replication: Neo4j does allow writing through slaves, even then that’s being written to syncs with the master before returning to the client (writing through slaves works slower then writing directly to the master)
- Buffer writes using queues: this technique can be used in a high write load scenarios, in order to reduce contention. It enables to pause write operations without refusing client requests during maintenance periods.
- Global Clusters: Latency introduced by the physical separation of the regions can sometimes disrupt the coordination protocol. It is better to restrict master reelection by create slave-only databases
- Neo4j cluster, the full graph is replicated to each instance in the cluster
In order to avoid pitfalls we have to check the design for queryability
- Describe the client or end-user goals that motivate our model
- Rewrite these goals as questions to ask of our domain
- Identify the entities and the relationship that appear in these questions
- Translate these entities and relationships into Cypher path expressions
- Express the questions we want to ask of our domain as graph patterns using path expressions similar to the ones we used to model the domain
In this blog I will try to explain quickly what is a graphdb and how to eat it. First lets answer the question what is a Graph? A graph is a collection of vertices and edges (Say it little simpler graph is a set of nodes and the relationships that connect them)
Given an array nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position. Return the max sliding window.
Alembic is a lightweight database migration tool for usage with the SQLAlchemy Database Toolkit for Python.