From c60e7955bfa7ac3de7c707f7f8555180646e56f7 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Tue, 1 Oct 2024 19:14:24 +0300
Subject: [PATCH] Add metric for builds waiting for download slot

(cherry picked from commit f23ec71227911891807706b6b978836e4d80edde)
---
 src/hydra-queue-runner/build-remote.cc       | 1 +
 src/hydra-queue-runner/hydra-queue-runner.cc | 1 +
 src/hydra-queue-runner/state.hh              | 1 +
 3 files changed, 3 insertions(+)

diff --git a/src/hydra-queue-runner/build-remote.cc b/src/hydra-queue-runner/build-remote.cc
index e28ca7951..369a3a457 100644
--- a/src/hydra-queue-runner/build-remote.cc
+++ b/src/hydra-queue-runner/build-remote.cc
@@ -565,6 +565,7 @@ void State::buildRemote(ref<Store> destStore,
         /* Throttle CPU-bound work. Opportunistically skip updating the current
          * step, since this requires a DB roundtrip. */
         if (!localWorkThrottler.try_acquire()) {
+            MaintainCount<counter> mc(nrStepsWaitingForDownloadSlot);
             updateStep(ssWaitingForLocalSlot);
             localWorkThrottler.acquire();
         }
diff --git a/src/hydra-queue-runner/hydra-queue-runner.cc b/src/hydra-queue-runner/hydra-queue-runner.cc
index 9ad3bc292..01f3c9339 100644
--- a/src/hydra-queue-runner/hydra-queue-runner.cc
+++ b/src/hydra-queue-runner/hydra-queue-runner.cc
@@ -612,6 +612,7 @@ void State::dumpStatus(Connection & conn)
         {"nrActiveSteps", activeSteps_.lock()->size()},
         {"nrStepsBuilding", nrStepsBuilding.load()},
         {"nrStepsCopyingTo", nrStepsCopyingTo.load()},
+        {"nrStepsWaitingForDownloadSlot", nrStepsWaitingForDownloadSlot.load()},
         {"nrStepsCopyingFrom", nrStepsCopyingFrom.load()},
         {"nrStepsWaiting", nrStepsWaiting.load()},
         {"nrUnsupportedSteps", nrUnsupportedSteps.load()},
diff --git a/src/hydra-queue-runner/state.hh b/src/hydra-queue-runner/state.hh
index deee781df..11aa2882f 100644
--- a/src/hydra-queue-runner/state.hh
+++ b/src/hydra-queue-runner/state.hh
@@ -376,6 +376,7 @@ private:
     counter nrStepsDone{0};
     counter nrStepsBuilding{0};
     counter nrStepsCopyingTo{0};
+    counter nrStepsWaitingForDownloadSlot{0};
     counter nrStepsCopyingFrom{0};
     counter nrStepsWaiting{0};
     counter nrUnsupportedSteps{0};