When using VIRL Clusters, the IP address used to reach the User Workspace Manager and by VM Maestro will be that of the Controller.
Most users will install VIRL onto a single bare-metal or virtual machine node. Every node (router, switch, server, or Linux Container (LXC)) used within a given VIRL simulation runs on this single machine.
Depending on the number and type of nodes used, it is possible for a simulation to require more compute and memory resources than can supported by a single node.
VIRL on Openstack Clusters enables you to combine multiple nodes (up to five) into a cluster, and to distibute the nodes in large, resource-intenstive simulations across this cluster so they can take advantage of the additional compute and memory resources.
At a minimum, a cluster must be composed of one 'controller' and one 'compute' node. Today, VIRL clusters can be scaled to a maximum of one controller and four compute nodes.
|Controller||The primary VIRL node that includes a complete installation of the VIRL server software, including full compute, storage, and network functionality and all of the node and container images.|
|Compute node||A node that includes a partial installation of the VIRL server software that enables it to provide additional compute and networking resources for use by a VIRL simulation.|
|Cluster||A collection of nodes operating in concert. At a minimum, a cluster can be composed of one 'controller and one compute node.|
|VIRL Server Image||A standard VIRL installation source (OVA or ISO) that contains the full compliment of VIRL software.|
|VIRL Compute Image||A VIRL installation source (OVA or ISO) that contains only the VIRL software necessary to provide compute and networking services.|
To successfully deploy a VIRL OpenStack Cluster please ensure that the following minimum requirements are met:
Each node must have at least 8GB RAM and 4 CPU or vCPU cores.
Each node must support and expose Intel VT-x/EPT or AMD-V/RVI virtualization extensions.
Controllers must have at least 80GB of disk or virtual disk space available.
Compute nodes must have at least 40GB of disk or virtual disk space available.
Each node must have five physical or virtual network interfaces.
|Node-Type||VIRL Software Release|
|Controller||1.3.286 or later|
|Compute Node||1.3.286 or later|
Every bare-metal node, ESXi-node, and cluster-member must be configured to properly synchronize with a valid NTP clock source.
The VIRL networks are named 'Management', 'Flat', 'Flat1', 'SNAT', and 'INT'. These are used for management, Layer-2 and Layer-3 connectivity, and cluster control-plane and data-plane functions, respectively.
Each of the five required interfaces on a cluster member are connected to these networks in order, as shown below for both bare-metal and virtualized environments.
In bare-metal deployments multiple LAN switches or VLANs must be used to provide seamless, isolated connectivity for each of the VIRL networks. The five phyiscal network interfaces on each node are connected as illustrated below:
|Interface||Switch or VLAN|
In vSphere ESXi deployments multiple Port-Groups should used to provide seamless, isolated connectivity for each of the VIRL networks. The five virtual network interfaces (vNIC) on each virtual machine are connected as illustrated below:
|eth0||VM Network (default)|
In deployments where cluster-members are deployed across multiple vSphere ESXi hosts care must be taken to ensure that seamless connectivity is maintained for each VIRL network. This can be done in one of two ways:
Using a vSphere Distributed Virtual Switch (DVS). Please refer to VMware for details on DVS configuration.
Using physical network connections between network interfaces on each host that are associated with the VIRL networks / port-groups.
Regardless of the method used, the logical connectivity between ESXi hosts and within the VIRL OpenStack Cluster must be as illustrated below:
When configured for clusters, the VIRL controller and compute nodes use Virtual Extensible LAN (VXLAN) over the 'INT' / eth4 network to provide a communications path between virtual routers, switches, and other nodes within a simulation that exist on different compute nodes.
To account for the headers used by IP, UDP, VXLAN, and any 802.1Q headers that may be present while still allowing for 1500-byte frames to be conveyed between virtual end-points it is necessary to configure Ethernet Jumbo Frames on all physical and / or virtual switching elements which service the 'INT' / eth4 network between the VIRL controller and compute nodes.
Specifically, please ensure that the following requirements are met before deploying VIRL controller or compute nodes:
Any physical Ethernet switch providing connectivity between bare-metal or vSphere ESXi hosts must be configured to permit Jumbo Frames (either 9000 or 9216-bytes, whichever is the maximum). Configuring Jumbo Frames on physical Ethernet switches is beyond the scope of these instructions, so please obtain assistance from your network engineering or support team.
If using vSphere ESXi with a standard vSwitch use the vSphere C# or HTML5 client to configure the vSwitch to support 9000-byte frames:
If using a vSphere Distributed vSwitch use the vCenter Web client to configure the DVS to support 9000-byte frames:
VXLAN uses IP multicast to transport Layer-2 broadcast, unknown end-point, and multicast traffic. To assist with end-point discovery and group-management please ensure that the following requirements are met:
IGMP Snooping must be enabled on each physical or virtual switch used service the 'INT' / eth4 network between bare-metal or vSphere ESXi hosts used for VIRL clustering. IGMP Snooping is enabled by default on Cisco physical switches, Nexus 1Kv virtual switches, vSphere Standard, and vSphere Distributed Virtual Switches.
If you are using something other than these please obtain assistance from your network engineering or support team.
An IGMP Querier facility must be present to manage IGMPv3 groups and group-membership on the network used to service 'INT' / eth4. IGMP Queriers are generally provided by routers that provide interfaces for phyical or virtual networks. IGMP Queriers can also be provided by physical Ethernet switches, or by using 'mrouted' or 'pim' services on servers sharing the physical segment or VLAN.
If you are unsure that an IGMP Querier is present, or if traffic does not flow between nodes on different hosts once you've tested your cluster, pease obtain assistance from your network engineering or support team.
The default interface addressing convention for VIRL on OpenStack Clusters is described below. The adresses for the 'Management', 'Flat', 'Flat1', and 'SNAT' networks can and should be adjusted to suit your exact deployment requirements when necessary.
|eth0||DHCP or Static||DHCP or Static||DHCP or Static||DHCP or Static||DHCP or Static|
The Controller in a VIRL OpenStack Cluster is adapted from a VIRL standalone node. As such, start by using menu at the left to select and follow the full installation process appropriate to your target environment.
The first series of steps inform the new VIRL standalone node that it will be operating in a cluster:
Login to the controller at the IP address recording during installation using the username 'virl' and password 'VIRL':
Make a copy of the VIRL configuration file 'virl.ini':
Open 'virl.ini' using the 'nano' editor:
Locate the configuration element 'virl_cluster: FALSE' and change its value to 'TRUE'.
Next you must identify how many compute nodes - from 1 to 4 - will be present in the cluster:
Locate the configuration element for the first compute node - 'compute1_active:' - and if found to be 'FALSE' - change its value to 'TRUE'.
Repeat for each additional compute node to be included in the cluster, from 2 to 4.
Save and apply the configuration changes:
Enter 'Control-X', 'Y' and 'Enter' to save the file and exit.
Apply the changes and update the controller's Salt configuration using the following commands:
Continue configuring the controller using the User Workspace Manager (UWM):
Open a browser and navigate to the the controller's UWM interface - 'http://<controller-ip-address>:19400'.
Login using username 'uwmadmin' and password 'password'
Select 'VIRL Server' from the menu.
Select 'System Configuration'.
The 'System Configuration' page will include tabs for each of the enabled compute nodes.
For each compute node in your cluster, select the appropriate tab and adjust its configuration to match your environment.
Once you have made all of the necessary changes select the 'Apply Changes' button and follow the instructions that are provided to reconfigure VIRL.
You must now restart the controller in order to finalize the configuration and services:
Restart the controller:
Compute nodes are installed using specialized OVAs or ISOs named 'compute.n.n.n.ova' or 'compute.n.n.n.iso', respectively. Please refer to your license confirmation email for information on how to download these installation sources.
The installation of a compute node starts as an abbreviated version of a standalone installation:
Download the compute node OVA or ISO files, 1 through up to 4, depending on the number you wish to deploy.
Deploy each of the OVAs or ISOs to a different server in your vCenter / ESXi environment (using the compute node OVAs) or to a different bare metal server (using the compute node ISOs).
Boot the newly deployed compute-node OVA or bare metal server.
Once each compute node has been deployed and booted, continue by validating connectivity to the controller and enabling the CML compute node software using the steps below:
Login to the compute node using the username 'virl' and password 'VIRL':
Ensure that connectivity to the controller exists:
Once the controller and each compute node has been deployed, you should validate that the cluster is properly configured and operational:
Login to the controller at the IP address recording during installation using the username 'virl' and password 'VIRL':
Verify that each compute node is registered with OpenStack Nova:
In the example below there are five 'nova-compute' services registered - one on the controller and another for each compute node that has beeen deployed:
Verify that each compute node is registered with OpenStack Neutron
In the example below there are five 'Linux bridge agents' registered - one on the controller and another for each compute node that has beeen deployed:
At this point your VIRL OpenStack Cluster should be fully operational and you should be able to start a VIRL simulation and observe all of the nodes become 'Active'.
In situations where communications is lost between the controller and a compute node, or if a compute node becomes inoperable, you can determine the state of each compute node from the controller using the 'nova service-list'' and 'neutron agent-list' commands you learned above.
For example, in the illustration below communications has been lost with 'compute4'. Observe that Nova shows the node as 'down', and Neutron shows the agent as 'xxx' (dead):
In this circumstances proper operation may be restored by restarting the affected node.
If restarting the compute node does not restore proper operation you may also want to check that the node has associated with a valid NTP clock source:
Valid peer associations are indicated by a '*' alongside the clock-source name, as illustrated:
To add additional compute nodes to an existing VIRL cluster:
Login to the controller at the IP address recording during installation using the username 'virl' and password 'VIRL'.
Edit '/etc/virl.ini' and set the configuration element for the new compute node to 'True'.
Apply the changes and update the controller's cluster configuration:
Complete the instructions for 'Compute Node Deployment' for the new compute node.
Complete the instructions in 'Cluster Validation' to ensure that the new compute node was properly deployed.
The primary reason for deploying a VIRL cluster is to simulate large complex topologies, but these simulations can be very taxing on VIRL compute and networking resources. The following guidelines should be followed to minimize simulation start times and ensure successful launches.
By default VIRL projects permit 200 instances (nodes), 200 vCPUs, and 512000MB of RAM. Running large simulations may require that you increase these limits using the UWM. For example:
Enabling RAMdisk on systems with greater than 32GB of memory will improve simulation start times by caching instances of router, switch, and other node images in memory, rather than reading images from disk for each node:
When working with very large (>100 nodes) simulations it is recommended that the nodes be started in groups of 100 or less. This can be achieved by selecting groups of nodes in VM Maestro and exluding them from launch, as shown:
Once the nodes that were not excluded have started, select the nodes that were excluded - again in groups of 100 or less - and start them, as shown:
The following configuration elements defiend in '/etc/virl.ini' or via the UWM are used to define VIRL OpenStack Cluster configurations:
|computeN_active||False||Specifies the absense or presence of the compute node 'N' in the cluster.||Set to 'True' for each available compute node (1 through 4).|
|computeN_nodename||computeN||Specifies the hosname associated with the compute node.||This field must match the nodename defined on the compute node.|
|computeN_public_port||eth0||Specifies the name of the port used to reach the Internet on the compute node.||This field must match exactly the public port name and format specified on the compute node.|
|computeN_using_dhcp_on_the_public_port||True||Specifies the addressing method used for the public port on the compute node.||Set to 'False' if using Static IP addressing.|
|computeN_static_ip||10.10.10.10||The Static IP address assigned to the public port.||Not used if DHCP is enabled. Review and modify to match deployment requirements.|
|computeN_public_netmask||255.255.255.0||The network mask assigned to the public port.||Not used if DHCP is enabled. Review and modify to match deployment requirements.|
|computeN_public_gateway||10.10.10.1||The IP address of the default gateway assigned to the public port.||Not used if DHCP is enabled. Review and modify to match deployment requirements.|
|computeN_first_nameserver||126.96.36.199||The IP address of the first name-server assigned to the public port.||Not used if DHCP is enabled. Review and modify to match deployment requirements.|
|computeN_second_nameserver||188.8.131.52||The IP address of the second name-server assigned to the public port.||Not used if DHCP is enabled. Review and modify to match deployment requirements.|
|computeN_l2_port||eth1||The name of the first layer-2 network port ('Flat') on the compute node.||This field must match exactly the name and format specified on the compute node.|
|computeN_l2_address||172.16.1.24N||The IP address assigned to the first layer-2 network port ('Flat') on the compute node.||This field must match exactly the IP address specified on the compute node. 'N must match the nodename / position in the cluster.|
|computeN_l2_port2||eth2||The name of the second layer-2 network port ('Flat1') on the compute node.||This field must match exactly the name and format specified on the compute node.|
|computeN_l2_address2||172.16.2.24N||The IP address assigned to the second layer-2 network port ('Flat1') on the compute node.||This field must match exactly the IP address specified on the compute node. 'N must match the nodename / position in the cluster.|
|computeN_l3_port||eth2||The name of the layer-3 network port ('SNAT') on the compute node.||This field must match exactly the name and format specified on the compute node.|
|computeN_l3_address||172.16.3.24N||The IP address assigned to layer-3 network port ('SNAT') on the compute node.||This field must match exactly the IP address specified on the compute node. 'N must match the nodename / position in the cluster.|
|computeN_internalnet_ip||172.16.10.24N||The IP address assigned to internal / cluster network interface ('eth4').|
The default configuration elements for each compute node in a VIRL OpenStack Cluster are as follows:
|Compute Node 1||Compute Node 2||Compute Node 3||Compute Node 4|