15370: Add dispatchcloud loopback driver.

[arvados.git] / lib / dispatchcloud / worker / pool.go

diff --git a/lib/dispatchcloud/worker/pool.go b/lib/dispatchcloud/worker/pool.go
index 37e3fa9882ddec9ad9a0623ad62f9b3d75d94433..66e0bfee910a236b46980f2db4b7c30850b3a759 100644 (file)
--- a/lib/dispatchcloud/worker/pool.go
+++ b/lib/dispatchcloud/worker/pool.go
@@ -13,6 +13,7 @@ import (
        "fmt"
        "io"
        "io/ioutil"
+       mathrand "math/rand"
        "sort"
        "strings"
        "sync"
@@ -774,6 +775,13 @@ func (wp *Pool) runProbes() {
 
        workers := []cloud.InstanceID{}
        for range probeticker.C {
+               // Add some jitter. Without this, if probeInterval is
+               // a multiple of syncInterval and sync is
+               // instantaneous (as with the loopback driver), the
+               // first few probes race with sync operations and
+               // don't update the workers.
+               time.Sleep(time.Duration(mathrand.Int63n(int64(wp.probeInterval) / 23)))
+
                workers = workers[:0]
                wp.mtx.Lock()
                for id, wkr := range wp.workers {
@@ -900,7 +908,7 @@ func (wp *Pool) loadRunnerData() error {
        }
        wp.runnerData = buf
        wp.runnerMD5 = md5.Sum(buf)
-       wp.runnerCmd = fmt.Sprintf("/var/lib/arvados/crunch-run~%x", wp.runnerMD5)
+       wp.runnerCmd = fmt.Sprintf("/tmp/arvados-crunch-run/crunch-run~%x", wp.runnerMD5)
        return nil
 }