NetScaler BLX cluster

A NetScaler BLX cluster is a group of BLX appliances working together as a single system. Each appliance of the cluster is called a node. A BLX cluster can include as few as 1 or as many as 32 BLX appliances as nodes.

Before you begin

This section lists prerequisites and points to note for setting up a BLX cluster:

• Make sure that you understand the Citrix ADC cluster feature. For more information, see Citrix ADC Cluster.

• Make sure that the following configurations are present on each Linux host of the BLX appliances:

  • NTP is configured on each Linux host:

    • For more information about configuring NTP on Oracle Linux, see Official Oracle Linux documentation.
    • For more information about configuring NTP on Ubuntu Linux, see Official Ubuntu Linux documentation.
    • For more information about configuring NTP on CentOS Linux, see Official CentOS Linux documentation.
  • Core dump is enabled on each Linux host for generating core dumps whenever the BLX appliance crashes.
  • Logging and rsyslog settings to reduce repeated log messages are configured on each Linux host for logs related to the BLX appliance.
• Cluster is supported for BLX appliances only in dedicated mode.

• All general prerequisites of a Citrix ADC cluster apply to BLX cluster as well.

  For more information about general prerequisites for setting up a BLX cluster, see General Prerequisites for Citrix ADC cluster.

• For information about the Citrix ADC features supported in a BLX cluster, see Citrix ADC features supportability matrix for BLX cluster.

• For information about automating Citrix ADC deployments using Terraform, see:
  • Citrix ADC Terraform provider on GitHub
  • Citrix ADC Terraform automation scripts on GitHub
• BLX cluster set ups are not supported in public cloud platforms, for example Amazon Web Services (AWS) cloud.

Limitations of a BLX cluster

A BLX cluster has the following limitations:

• INC mode is not supported.
• CLAG based traffic distribution is not supported.

• All limitations of a standalone BLX appliance apply to a BLX cluster as well.

  For more information about limitations of a BLX appliance, see BLX limitations.

Setting up a BLX cluster

For setting up a BLX cluster, follow the general procedure for setting up a Citrix ADC cluster at Citrix ADC Cluster. This docs set contains general information about Citrix ADC clusters. The information in this docs set applies for BLX cluster as well.