From da225d408bafd1d100d55f64adb28869b7c377e7 Mon Sep 17 00:00:00 2001 From: David Anderson Date: Mon, 2 Oct 2023 19:31:50 -0700 Subject: [PATCH] Updated Sporadic Applications (markdown) --- Sporadic-Applications.md | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/Sporadic-Applications.md b/Sporadic-Applications.md index 9499b48..d0139bb 100644 --- a/Sporadic-Applications.md +++ b/Sporadic-Applications.md @@ -2,22 +2,26 @@ BOINC was originally designed as a batch processing system: you submit jobs, they run (independently of each other) and eventually finish. But some potential uses of volunteer computing don't fit this model. -They may require that their apps run simultaneously on different computers, +They may require that apps run simultaneously on different computers, and perhaps that they communicate directly with each other. Examples include MPI-type parallel computing and distributed machine learning. + BOINC's 'sporadic application' mechanism is designed to support these types of systems, and to allow them to coexist with batch processing. - The jobs of a sporadic app run (i.e. are present in memory) all the time, like non-CPU-intensive jobs, but compute only some of the time. Like regular apps, a sporadic app can have multiple app versions. -Each of these app versions has a plan class, +Each of these has a plan class, which determines the processor usage (CPUs and GPUs) of its jobs. A project's BOINC scheduler can send multiple jobs for a given sporadic app, using the same or different app versions. +A BOINC project can provide any combination of +regular, sporadic, and non-CPU-intensive apps. +A client can be connected to multiple projects with sporadic apps. + Like regular jobs, a sporadic job can compute only when * computing (and GPU computing if relevant) is enabled by user preferences * there are sufficient processing resources and RAM @@ -122,5 +126,18 @@ enum SPORADIC_AC_STATE { extern void boinc_sporadic_set_ac_state(SPORADIC_AC_STATE); extern SPORADIC_CA_STATE boinc_sporadic_get_ca_state(); - ``` + +## Prioritization of sporadic apps + +In the initial implementation of sporadic apps (client 7.26), +sporadic apps have strict priority over regular apps. +Thus if a sporadic app does lots of computing +it can starve regular app. +If multiple sporadic apps compete for a resource (say, a GPU) +the prioritization is fixed; one of them can starve the others. + +In a later version, sporadic apps will be scheduled using the same +scheme that is used for regular apps, +in which resource share determines prioritization +and starvation is eliminated. \ No newline at end of file