How to load a huge graph into memory to repeatedly find shortest path between two given nodes?

I am writing an application in which I need to load a huge graph into memory and answer "shortest path between x and y" for different pairs of x and y. The graph is static and can be loaded once for all into main memory.

The query for shortest path between x and y is made by a UI written in PHP. How can I keep the graph loaded in memory and find the shortest path repeatedly in an efficient way ? Is writing a JA开发者_如何学CVA daemon going to help ?

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Sounds like you want to write a service/daemon which run all the time and keeps the data in memory. By huge, how big is it?

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You can use memcached to keep the graph loaded in memory. PHP can easily read/write data from memcached.

You would need to run memcached as a daemon / service on server.