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    <p>Your approach seems sound to me ...</p> <p>What you might have problems with however is ensuring <strong>causality</strong> between writes on separate subgraphs.</p> <p>If a writer alters subgraph A and another writer alters distinct subgraph B, but other read/write operations happen on subgraph C where A and B are in C then you need to ensure that the version of subgraph C aligns correctly with the versions of B and A.</p> <p>I would suggest a locking scheme in the DAG that incorporates subgraph locking for multiple read/single write from a given root. You will need to grep the graph for cyclic dependencies however to ensure that you don't get into a starvation/deadlock state within the graph.</p> <p>If your graph is <strong>distributed</strong> or your concurrent access has <strong>latency</strong> then your transaction system will be harder to implement and will likely require additional safeguards. </p> <p>Your versioning approach sounds fine providing your locking provisions ensure, in all cases that a set of revisions for nodes at any time T represent an <strong>integral state</strong> of the graph. The set of nodes and revisions at T = {n0, n1, n2, n3} and a concurrent revision bumping of subgraphs will pose the headache in keeping the entire set of revisions and nodes at T integral.</p> <p>As <a href="https://stackoverflow.com/questions/1159495/how-do-i-organize-multithreaded-access-to-a-graph/1159586#1159586">dfa suggests above</a>, the set of nodes and revisions at some point represents a changeset of the entire structure. Providing it has integrity, this represents the entire structure at some point in time.</p> <p>Remember: Time, Integrity, Causality and Concurrency</p> <p>Good Luck!</p>
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    1. POHow do I organize multithreaded access to a graph?
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    1. USCommunity
    1. USAiden Bell
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    1. COThanks for all the helpful advice!
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      1. USHanno Fietz
 

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