Add upper limit to exponential-backoff

scalar-labs · Oct 24, 2024 · 82acdb0 · 82acdb0
1 parent 9ff6675
commit 82acdb0
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/scalardb/src/scalardb/core.clj b/scalardb/src/scalardb/core.clj
@@ -15,15 +15,20 @@
 (def ^:const RETRIES 8)
 (def ^:const RETRIES_FOR_RECONNECTION 3)
 (def ^:private ^:const NUM_FAILURES_FOR_RECONNECTION 1000)
+(def ^:private ^:const MAX_WAIT_MILLIS 32000)
 (def ^:const INITIAL_TABLE_ID 1)
 (def ^:const DEFAULT_TABLE_COUNT 3)
 
 (def ^:const KEYSPACE "jepsen")
 (def ^:const VERSION "tx_version")
 
+(defn compute-exponential-backoff
+  [r]
+  (min MAX_WAIT_MILLIS (reduce * 1000 (repeat r 2))))
+
 (defn exponential-backoff
   [r]
-  (Thread/sleep (reduce * 1000 (repeat r 2))))
+  (Thread/sleep (compute-exponential-backoff r)))
 
 (defn- get-cassandra-schema
   "Only the current test schemata are covered

diff --git a/scalardb/test/scalardb/core_test.clj b/scalardb/test/scalardb/core_test.clj
@@ -152,3 +152,9 @@
                    (scalar/check-transaction-states test #{"tx"})))
       (is (spy/called-n-times? scalar/exponential-backoff 8))
       (is (spy/called-n-times? scalar/prepare-storage-service! 3)))))
+
+(deftest compute-exponential-backoff-test
+  (is (= 2000 (scalar/compute-exponential-backoff 1)))
+  (is (= 4000 (scalar/compute-exponential-backoff 2)))
+  (is (= 32000 (scalar/compute-exponential-backoff 5)))
+  (is (= 32000 (scalar/compute-exponential-backoff 10))))