Forum: Installation

Post: Minimum connectivity requirements

Minimum connectivity requirements
tfioreze
Aug 15, 2011
Is there any minimum connectivity requirement for a VoltDB Cluster connected to a single network switch (e.g., 100Mbps Ethernet cards)? And between switches (i.e., between two network segments)?

Best regards,
Tiago Fioreze
1Gbps advised
sebc
Aug 15, 2011
Tiago,

You'd definitely want a relatively fast network, or you would find your application to be network-bound very quickly. This is especially true when you run a rather basic Key/Value payload with "fat" payloads. So 1Gbps (or 10 if you can) is definitely the way to go.

Seb
To be clear, it will work
jhugg
Aug 15, 2011
Tiago,

You'd definitely want a relatively fast network, or you would find your application to be network-bound very quickly. This is especially true when you run a rather basic Key/Value payload with "fat" payloads. So 1Gbps (or 10 if you can) is definitely the way to go.

Seb


I agree with Seb totally, but wanted to clarify that nothing will prevent VoltDB from running on a 100mb network. The only catch is the network will, in most cases, limit the performance substantially.
Can network congestion lead to network partition detection?
tfioreze
Aug 16, 2011
Thanks for the clarification. Yet regarding this question of network connectivity... let's imagine a scenario in which we have two network segments (i.e., a connection between two switches) interconnected through a link that time to time becomes congested. Can this bottleneck situation lead to a false positive network partition detection? And by the way... how does VoltDB network partition detection system work?
Congestion
rbetts
Aug 16, 2011
Thanks for the clarification. Yet regarding this question of network connectivity... let's imagine a scenario in which we have two network segments (i.e., a connection between two switches) interconnected through a link that time to time becomes congested. Can this bottleneck situation lead to a false positive network partition detection? And by the way... how does VoltDB network partition detection system work?


If congestion prevents communication between two segments of the cluster, this can not be distinguished from node failure and a network partition may be detected. Whether this is a false positive or a legitimate failure is perhaps debatable. VoltDB nodes need to communicate to make progress. The partition detection feature is described in documentation:


[TD="class: xl65, width: 467"]http://www.voltdb.com/community/documentation.php





You can configure the heartbeat interval to make the system a little more tolerant of problems like congestion. See the heartbeat section of:

[TD="class: xl66, width: 467"]http://www.voltdb.com/community/documentation.php


or

[TD="class: xl66, width: 467"]http://www.voltdb.com/community/documentation.php


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*--Ryan.