Replacing vCD SSL Certificates in a Multi Cell Environment

Manish Jha

After a long wait I finally got chance to work on vCloud Director ssl certificates. This was the only component in my lab which was still using self-signed certs and that encouraged me to do something new in lab.

A note on vCD SSL certificates

vCloud Director like any other VMware product needs a certificate to be installed on the device that it uses for communication with the other products. By default vCD uses a self-signed certificate. If you have a certificate authority in your environment then you can get the certs created in advance before installing vCloud director and save your self from pain of messing with certificates at later stages.

vCD has 2 IP address which allows support for 2 different SSL endpoints (http and consoleproxy). Each endpoint requires its own SSL certificate. vCloud Director uses a java keystore to read its SSL certificates from.  In a Multi-cell environment you need to create 2 certificates for each cell and import the certificates into vcd java keystore.… Read More

Troubleshooting Failed Org Network Creation in vCloud Director

Manish Jha

Today while working in my lab, I observed that while creating a new VDC in vCD was failing because org network failed to create.

On navigating to Org VDC list and clicking on error, it read the error load and clear that org vdc network can’t be created.

vcd-1

On navigating to Org VDC Networks section and clicking on error, I was able to identify what has caused the network creation failure.

vcd-2

The error stack was reading as below:

… Read More

Troubleshooting Mysterious Catalog Item in vCloud Director

Manish Jha

Few days back while working on one of the customer ticket, I came across an incident where customer was reporting that he is not able to see one of his template in his catalog. He sent the VM via ODT to vCloud Air to be imported in his catalog.

I verified that VM was missing from catalog but was present in vCenter. I tried to import the VM again in Catalog by selecting the option “Import from vSphere” but to my surprise the VM was showing up in the list for selection.

corpsql01 not listing

I have never seen such behaviour in VCD. Even if import of template is failed midway, the item is listed in catalog with a question mark against it and status of item reads as “failed to create“

After scratching my head for 15-20 minutes and checking with my peer if he had seen any such issue in past, I decided to employ API calls for catalog query (GUI is a big fat lier sometimes) and to my surprise I was seeing 2 entries for catalog items.… Read More

RabbitMQ Clustering

Manish Jha

In the last post of this series, we learned how to install/configure RMQ for vCloud Director. This post is an extension of my last post where I will be adding one more node to my RMQ setup to form a cluster for high availability.

What data is replicated in an RMQ Cluster?

All data/state required for the operation of a RabbitMQ broker is replicated across all nodes. An exception to this is message queues, which by default reside on one node, though they are visible and reachable from all nodes. To replicate queues across nodes in a cluster, see the documentation on high-availability

Note: Before proceeding with cluster formation, please ensure the following:

1: Use the same version of Erlang and RMQ server rpm which is installed on the master node.

2: RMQ nodes address each other using domain names, either short or FQDNs. Therefore hostnames of all cluster members must be resolvable from all cluster nodes, as well as machines on which command line tools such as rabbitmqctl might be used.… Read More

Installing RabbitMQ for vCloud Director

Manish Jha

In this post, I will demonstrate how to install RMQ for vCloud Director. Before jumping into any lab activity, let’s learn first what is RabbitMQ and why we need it.

What is RabbitMQ?

RabbitMQ is an open-source message-queuing software that helps facilitate message exchange between 2 or more applications. The exchange of messages is done via a queue which is defined by the administrator. An application can publish a message to the queue which can be retrieved or consumed by a different application.

A message can include any kind of information for example, it could have information about a process/task that should start on another application may be on another server or it could be just a simple text message.

The queue-manager software stores the messages until a receiving application connects and takes a message off the queue. The receiving application then appropriately processes the message.

How does it work?

RabbitMQ works by offering an interface, that connects message senders (Publishers) with receivers (Consumers) through an exchange (Broker) which distributes the data to relevant lists (Message Queues).… Read More

VM replication state going to ‘Not Active’ as soon as vm is configured for replication

Manish Jha

After a long back I dived into my lab yesterday and was working again on setting up DR to vCloud Air.I have wrote few blog posts in past on vSphere Replication and DR to vCloud Air using VR. If you are interested in reading those posts, you can read them from below links

1: Replicating and Recovering VM’s using vSphere Replication

2: Disaster Recovery with vcloud Air

3: Replicate VM to vCloud Air using vSphere Replication

This time in my lab I noticed that all my VM’s replication state were going to ‘Not Active’ as soon as its configured for replication. This was a brand new setup and I was sure that I followed all required steps in deploying and configuring the replication appliance. This was strange as I never faced this issue before.

repn-1.PNG

in hms.log on my on-prem VR appliance I was seeing the same messages about replication not active

hms.log… Read More

Learning Apache Cassandra-Part-5-Getting Familiar With Nodetool

Manish Jha

In last post of this series we learnt about how to add nodes in a cassandra cluster. If you have missed earlier posts of this series

then you can read them from below links:

1: Introduction to Cassandra

2: Understanding Cassandra Read/Write Mechanism

3: Installing Cassandra on RHEL6

4: Adding Node To Cassandra Cluster

In this post we will explore nodetool and will see how we can manage a cassandra cluster using nodetool utility.

What is nodetool?

The nodetool utility is a command line interface for managing a cluster. It provides a simple command line interface to expose operations and attributes available with cassandra.

There are hundreds of options available with nodetool utility and in this post I will cover only those which ae used more often.

Note: This post is suitable for those admins who are not sevrice owners of cassandra nodes/cluster but have to interact with cassandra day in day out in their infrastructure.… Read More

Learning Apache Cassandra-Part-4-Adding Node To Cassandra Cluster

Manish Jha

In last post of this series we learnt how to install cassandra on Rhel 6. In this post we will look into additional configuration parameter that is needed to configure in order to facilitate other nodes to join the cassandra cluster.

If you have missed earlier posts of this series then you can read them from below links:

1: Introduction to Cassandra

2: Understanding Cassandra Read/Write Mechanism

3: Installing Cassandra on RHEL6

At the moment we have one node cassandra cluster. Before going ahead and installing cassandra on other nodes, we will first perform following configuration changes in cassandra.yaml file.

Navigate to cassandra.yaml file which is located in cassandra_install_dir/conf folder. Open the file in editor of your choice and look for following options:

  • Listen_address: Address where gossip will be listening to. This address can’t be localhost or 0.0.0.0, because the rest of nodes will try to connect to this address.
… Read More

Learning Apache Cassandra-Part-3-Installing Cassandra on RHEL6

Manish Jha

In last 2 posts of this series we learnt about Cassandra architecture and understood the cassandra Read/Write process.

If you have missed earlier posts of this series then you can read them from below links:

1:Introduction to cassandra

2: Understanding Cassandra Read/Write Mechanism

In this post we will learn about installing cassandra on Redhat Linux.

Before jumping into lab and start with installation, I want to touch down on few concepts first which will help in understanding installation process.

Bootstrapping

Bootstrapping is the process in which a newly-joining node gets the required data from the neighbors in the ring, so it can join the ring with the required data. Typically, a bootstrapping node joins the ring without any state or token and understands the ring structure after starting the gossip with the seed nodes; the second step is to choose a token to bootstrap.

During the bootstrap, the bootstrapping node will receive writes for the range that it will be responsible for after the bootstrap is completed.… Read More

Learning Apache Cassandra-Part-2:Understanding Cassandra Read/Write Mechanism

Manish Jha

In first post of this series we discussed about what is cassandra, what are the benefits of using cassandra. We also discussed a little bit about from where cassandra came and finally we looked at the architecture of cassandra and discussed some important terms like snitch, gossip, data replication, partitioner etc.

In this post we will see how cassandra Read/Write mechanism works.

Let’s discuss about some key components of cassandra first before discussing about Read/Write. Important components of cassandra can be summarized as below:

1: Node – This is the most basic component of cassandra and it is the place where data is stored.

2: Data Center – In simplest term a datacenter is nothing but a collection of nodes. A datacenter can be a physical datacenter or virtual datacenter.

3: Cluster – Collection of many data centers is termed as cluster.

4: Commit Log – Every write operation is written to Commit Log.… Read More