21227: Use a separate global requestLimiter for each target host.

[arvados.git] / sdk / go / arvados / limiter.go

diff --git a/sdk/go/arvados/limiter.go b/sdk/go/arvados/limiter.go
index f62264c636f96dfa4b55ff0d581fc8cd50b05c09..dc944160ab2dd5d459a31fa2386ebe9a5f6bb2c3 100644 (file)
--- a/sdk/go/arvados/limiter.go
+++ b/sdk/go/arvados/limiter.go
@@ -13,11 +13,15 @@ import (
        "time"
 )
 
-var requestLimiterQuietPeriod = time.Second
+var (
+       requestLimiterQuietPeriod        = time.Second
+       requestLimiterInitialLimit int64 = 8
+)
 
 type requestLimiter struct {
        current    int64
        limit      int64
+       maxlimit   int64
        lock       sync.Mutex
        cond       *sync.Cond
        quietUntil time.Time
@@ -33,6 +37,7 @@ func (rl *requestLimiter) Acquire(ctx context.Context) {
        if rl.cond == nil {
                // First use of requestLimiter. Initialize.
                rl.cond = sync.NewCond(&rl.lock)
+               rl.limit = requestLimiterInitialLimit
        }
        // Wait out the quiet period(s) immediately following a 503.
        for ctx.Err() == nil {
@@ -137,9 +142,12 @@ func (rl *requestLimiter) Report(resp *http.Response, err error) bool {
                        increase = 1
                }
                rl.limit += increase
-               if max := rl.current * 2; max > rl.limit {
+               if max := rl.current * 2; max < rl.limit {
                        rl.limit = max
                }
+               if rl.maxlimit > 0 && rl.maxlimit < rl.limit {
+                       rl.limit = rl.maxlimit
+               }
                rl.cond.Broadcast()
        }
        return false