Network Requirements

For most production environments, TimesTen Scaleout requires a single private internal network and at least one external network. These topics describe the requirements for those networks.

Internal Network

Instances in a grid communicate with each other over a single internal network using the TCP protocol. TimesTen Scaleout uses this network to perform all SQL, backup, and management operations required by the grid and its databases. In addition, instances communicate with membership servers through this network. Membership servers use this network to communicate among themselves.

Ensure that your internal network has these characteristics:

High bandwidth. The faster the network the better, in terms of throughput (gigabits per second). For production environments, ensure at minimum a 10 Gigabit Ethernet network or equivalent.
Low latency. To reduce network latency (time to transmit a message from one host to another) to a minimum, the hosts and membership servers attached to your internal network should either:
- Span a single data center within a small number of racks.
- Span multiple data centers within a small geographic region (city or suburb) connected by a metropolitan area network (MAN). Only recommended with a 10 GbE network or better.
- Not span multiple data regions (states or provinces) connected by a wide area network (WAN).
IPv4 or IPv6 addresses.
No network address translation (NAT).
No TCP packet filtering.

For an on-premises environment, ensure your internal network meets these requirements:

If your internal network consists of a single network segment, all hosts are connected to a single Ethernet switch or equivalent.
If your internal network consists of multiple network segments, those segments are connected through bridges instead of IP routers.
If your internal network uses a MAN, ensure that the MAN can provide the required bandwidth and latency for your workload.

Syntax for Internal Addresses

When you define a host for your grid, you must specify a single value for the internal address of that host. Optionally, you specify a value for that the external address of that host. The value you specify for the internal address of a host can be either an IPv4 address, an IPv6 address or a name that resolves into one or more IPv4 or IPv6 addresses. For example:

A dot-decimal IPv4 address such as 192.168.1.1
A colon-hexadecimal IPv6 address such as 2606:fe80::f816:3eff:fe15:44b3
A name specified in the /etc/hosts file such as host1
A name defined in a private Domain Name Server (DNS) such as int-host1.example.com

If you use a name to define the internal address of a host:

If the name resolves to multiple IP addresses, those addresses must be on the same network segment.
Every host in the grid must be able to resolve a name to the same addresses. For example, if you use the hosts file to define a name, then the hosts file on each host in the grid must contain identical entries for that name.

External Network

A grid may optionally use one or more public external networks. These networks enable applications running on machines that are not part of the grid to create client/server connections to databases in the grid. You cannot perform any grid or database management operations through an external network.

While the performance of an external network is important, it is less important than the performance of the internal network. If the internal network performs poorly or unreliably, the grid and its databases may perform poorly or unreliably for all users. Conversely, if an external network performs poorly or unreliably, it may only affect the applications connected to the databases in the grid through that network. As a result, there are fewer requirements for an external network than for the internal network.

Your external networks should have these characteristics:

Bandwidth based on the requirements of your client/server applications.
Latency based on the requirements of your client/server applications.
IPv4 or IPv6 addresses.
TCP connectivity to the server port of each data instance.
Any combination of network technologies (VPN, routers, LAN, WAN, etcetera).

If your grid uses a single external network, then the value you specify for the external address of a host can be in any of the forms described in Syntax for Internal Addresses. If your grid uses multiple external networks, then you must use a name to define the external address of a host. The name must resolve to at least one IP address for each external network you use.