ctubbsii commented on PR #2665: URL: https://github.com/apache/accumulo/pull/2665#issuecomment-1156539782
Okay, thanks. That helps. I guess I was thinking the current dispatcher ran in the client side. So, using scan hints wouldn't even work the way I imagined it. We need the scan server dispatcher plugin to run on the client side first. A few thoughts based on my new understanding: 1. The client side dispatcher concept is very different from the executor dispatching that is done in the tserver, but has a very similar name. It might be helpful to have this named completely differently... like "server chooser" or "tablet scanner server type selector" or something along those lines (not necessarily as verbose as that latter one... but something to make it clearly distinct from the executor pool dispatching inside the server). 2. It would be nice if the scan server dispatching inside the scan server worked the same as the existing per-table dispatcher inside the tserver. Ideally, the same dispatcher would work in both servers, without a new dispatcher SPI specifically for the scan server. One thing is clear, my previous suggestion about using scan hints can be thrown out. Those are specifically scan executor hints, and should be used only by the dispatcher inside the server, because the dispatcher inside the server dispatches to an executor. The choice of which server type is an entirely different kind of dispatching, not to a scan executor, but to a server. So, that does imply a new kind of SPI or configuration to do the server selection inside the client (or... a different client entirely rather than modify the existing client). This is what I'm picturing now (very similar to yours, but tries to keep the servers similar, and makes server type selection more explicit):  -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
