How can I detect clock skew among nodes in Azure roles?

Question

I have a time sensitive operation that needs to be aware of clock skew among other computers, and /or guard against such a thing. How can I detect or guard against clock skew?

In my case I'm writing a compressed datetime stamp to Azure Blob. It would be disasterous if different nodes would intererpret that datetime stamp differently (as it can occur during a leap day, or leap second)

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More info

I'm trying to detect clock skew in local node current time.

Each node will be writing time sensitive information to a Blob/Table. If the timestamp is older than X than certain actions will occur. If the time is not synchronized, data may be lost or corrupted.

Possible solution

Perhaps I can have each node write its current date to blob storage (32 bytes) on a regular interval, and then query that on a routine basis.

Answer 1

There are a few .NET NTP client APIs that will tell you the skew between a local node time and time on a NTP time server. For example:

• Rebex (see "Determining the time difference between the local time and a time server")
• ComponentSpace
• ActiveSocket Toolkit

You could use an NTP client to store both the local time and skew in your blob. When you read the blob on a different node, you could compute that node's local time and skew and compare it to the blob's stored time and skew.