title: How do I process a graph that is constantly updating, with low latency?
body: <p>I am working on a project that involves many clients connecting to a server(servers if need be) that contains a bunch of graph info (node attributes and edges). They will have the option to introduce a new node or edge anytime they want and then request some information from the graph as a whole (shortest distance between two nodes, graph coloring, etc).</p>
  
  <p>This is obviously quite easy to develop the naive algorithm for, but then I am trying to learn to scale this so that it can handle many users updating the graph at the same time, many users requesting information from the graph, and the possibility of handling a very large (500k +) nodes and possibly a very large number of edges as well.</p>
  
  <p>The challenges I can foresee:</p>
  
  <ul>
  <li>with a constantly updating graph, I need to process the whole graph every time someone requests information...which will increase computation time and latency quite a bit</li>
  <li>with a very large graph, the computation time and latency will obviously be a lot higher (I read that this was remedied by some companies by batch processing a ton of results and storing them with an index for later use...but then since my graph is being constantly updated and users want the most up to date info, this is not a viable solution)</li>
  <li>a large number of users requesting information which will be quite a load on the servers since it has to process the graph that many times</li>
  </ul>
  
  <p>How do I start facing these challenges? I looked at hadoop and spark, but they seem have high latency solutions (with batch processing) or solutions that address problems where the graph is not constantly changing.</p>
  
  <p>I had the idea of maybe processing different parts of the graph and indexing them, then keeping track of where the graph is updated and re-process that section of the graph (a kind of distributed dynamic programming approach), but im not sure how feasible that is.</p>
  
  <p>Thanks!</p>