Cassandra

Introduction

Apache Cassandra is an open-source distributed database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers robust support for clusters spanning multiple datacenters, with asynchronous masterless replication allowing low latency operations for all clients. Apache Cassandra is the only NoSQL solution that can accommodate the complex requirements of modern line-of-business applications and is monitored through JMX. It is architected from the ground up for real-time enterprise databases that require vast scalability, high-velocity performance, flexible schema design, and continuous availability.

The benefits Cassandra delivers to your business include:

• Elastic scalability– Allows you to easily add capacity online to accommodate more customers and more data whenever you need. Always on architecture – Contains no single point of failure (as with traditional master/slave RDBMS’s and other NoSQL solutions) resulting in continuous availability for business-critical applications that can’t afford to go down, ever.
• Fast linear-scale performance– Enables sub-second response times with linear scalability (double your throughput with two nodes, quadruple it with four, and so on) to deliver response time speeds your customers have come to expect.
• Flexible data storage– Easily accommodates the full range of data formats – structured, semi-structured and unstructured – that run through today’s modern applications. Also dynamically accommodates changes to your data structures as your data needs evolve.
• Easy data distribution– Gives you maximum flexibility to distribute data where you need by replicating data across multiple data centers, the cloud and even mixed cloud/on-premise environments. Read and write to any node with all changes being automatically synchronized across a cluster.
• Operational simplicity– with all nodes in a cluster being the same, there is no complex configuration to manage so administration duties are greatly simplified.
• Transaction support – Delivers the “AID” in ACID compliance through its use of a commit log to capture all writes and built-in redundancies that ensure data durability in the event of hardware failures, as well as transaction isolation, atomicity, with consistency being tunable.

In addition, Cassandra requires no new equipment and is very economical to run. It also provides data compression (up to 80% in some cases), eliminates the hassle of memory caching software (e.g., memcached), and provides a query language (CQL) that’s similar to SQL, flattening the learning curve.

Discovery using the agent

Collector Type: Agent

Category: Application Monitors

Application Name: Cassandra

Global Template Name : Linux - Cassandra2 Template

Pre-requisite : Please refer to JMX Monitoring to enable JMX in the java application.

Parameters

Note: All field attributes are mandatory, use default values wherever applicable.

Collected Metrics

Discovery using the gateway

The administrator can deploy a gateway to support Cassandra agentless monitoring. The gateway establishes a connection to the database using the management profile, collects metrics from the templates, and starts monitoring.

To monitor Cassandra:

• Associate appropriate database credentials to the discovered database.
• Assign one or more database-specific global templates on the device.

Choose one of the following management mechanisms to discover Cassandra servers and add them to your inventory:

• WMI

• SSH

• SNMP

• (Optional)Manually add a database server to the infrastructure inventory.

  1. Select Infrastructure.
  2. Click Settings > Resource > Add.
  3. From the Add Device window, enter the required details such as Device Type and Management Profile.
  4. Click Save.

Prerequisites

• Install gateway version 5.0.0 or later.
• Map a suitable gateway management profile to a resource.
• Create credentials with type JMX before assigning a template to a resource. The Port, Connection Time-out, and Is Secure values are not used to create credentials.
• Configure JMX in the end device.

View resource metrics

The gateway monitors the application using the assigned templates and displays the results in graphical format. To view resource metrics, click the desired Database Resource Name > Resource Details > Metrics.

Troubleshooting

Verify the following if the graphs are generated incorrectly:

• The resource is accessible and Telnet is established for the IP address and port.
• Valid credentials are used for the resource.

If you experience Cassandra monitoring issues, try the following troubleshooting steps:

1. Verify server and gateway connectivity using Ping - ping IP Address

Example - ping 12.26.105.173

2. Verify Telnet-to-server listening port connectivity - telnet IP Address Port

Example - telnet 172.26.105.173 9988

Supported templates

• Cassandra ClientReq Storage Threadpool Template
• Cassandra ColumnFamily Template
• Cassandra Jvm Template
• Cassandra Keyspace Template

After selecting the templates, you can:

• Assign Cassandra templates from Setup or at the device level.
• Customize default configuration parameter values while assigning the template.

Resource template configuration parameters

Supported metrics