Decreasing default sleep time for refreshNow() calls, sleep time now … (#160)

*Issue #, if available:*
#154

*Description of changes:* Decreased default sleep time for refreshNow()
calls to be between 50 and 100 ms, also made this value configurable


By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

---------

Co-authored-by: Caitlin Russell <[email protected]>

Author: crus-umich

src/main/java/com/amazonaws/secretsmanager/caching/SecretCacheConfiguration.java

@@ -34,6 +34,12 @@ public class SecretCacheConfiguration {
     /** The default version stage to use when retrieving secret values. */
     public static final String DEFAULT_VERSION_STAGE = "AWSCURRENT";
 
+    /** 
+     * The default maximum jitter value in milliseconds to use when forcing a refresh.
+     * This prevents continuous refreshNow() calls by adding a random sleep.
+     */
+    public static final long DEFAULT_FORCE_REFRESH_JITTER = 100;
+
     /** The client this cache instance will use for accessing AWS Secrets Manager. */
     private SecretsManagerClient client = null;
 
@@ -60,6 +66,13 @@ public class SecretCacheConfiguration {
      */
     private String versionStage = DEFAULT_VERSION_STAGE;
 
+    /**
+     * When forcing a refresh using the refreshNow method, a random sleep
+     * will be performed using this value.  This helps prevent code from
+     * executing a refreshNow in a continuous loop without waiting.
+     */
+    private long forceRefreshJitterMillis = DEFAULT_FORCE_REFRESH_JITTER;
+
     /**
      * Default constructor for the SecretCacheConfiguration object.
      *
@@ -237,4 +250,45 @@ public SecretCacheConfiguration withVersionStage(String versionStage) {
         return this;
     }
 
+    /**
+     * Returns the refresh jitter that is used when force refreshing secrets.
+     *
+     * @return The maximum jitter sleep time in milliseconds used with refreshing secrets.
+     */
+    public long getForceRefreshJitterMillis() {
+        return this.forceRefreshJitterMillis;
+    }
+
+    /**
+     * Sets the maximum sleep time in milliseconds between force refresh calls.
+     * This value is used to prevent continuous refreshNow() calls in tight loops
+     * by adding a random sleep between half the configured value and the full value.
+     * The value must be greater than or equal to zero.
+     *
+     * @param forceRefreshJitterMillis
+     *            The maximum sleep time in milliseconds between force refresh calls.
+     * @throws IllegalArgumentException if the value is negative
+     */
+    public void setForceRefreshJitterMillis(long forceRefreshJitterMillis) {
+        if (forceRefreshJitterMillis < 0) {
+            throw new IllegalArgumentException("Force refresh jitter must be greater than or equal to zero");
+        }
+        this.forceRefreshJitterMillis = forceRefreshJitterMillis;
+    }
+
+    /**
+     * Sets the maximum sleep time in milliseconds between force refresh calls.
+     * This value is used to prevent continuous refreshNow() calls in tight loops
+     * by adding a random sleep between half the configured value and the full value.
+     *
+     * @param forceRefreshJitterMillis
+     *            The maximum sleep time in milliseconds between force refresh calls.
+     * @return The updated ClientConfiguration object with the new refresh sleep time.
+     * @throws IllegalArgumentException if the value is negative
+     */
+    public SecretCacheConfiguration withForceRefreshJitterMillis(long forceRefreshJitterMillis) {
+        this.setForceRefreshJitterMillis(forceRefreshJitterMillis);
+        return this;
+    }
+
 }

src/main/java/com/amazonaws/secretsmanager/caching/cache/SecretCacheObject.java

@@ -37,13 +37,6 @@ public abstract class SecretCacheObject<T> {
      */
     private static final long BACKOFF_PLATEAU = EXCEPTION_BACKOFF * 128;
 
-    /**
-     * When forcing a refresh using the refreshNow method, a random sleep
-     * will be performed using this value.  This helps prevent code from
-     * executing a refreshNow in a continuous loop without waiting.
-     */
-    private static final long FORCE_REFRESH_JITTER_SLEEP = 5000;
-
     /** The secret identifier for this cached object. */
     protected final String secretId;
 
@@ -215,10 +208,11 @@ public boolean refreshNow() throws InterruptedException {
         // When forcing a refresh, always sleep with a random jitter
         // to prevent coding errors that could be calling refreshNow
         // in a loop.
+        long jitter = this.config.getForceRefreshJitterMillis();
         long sleep = ThreadLocalRandom.current()
                 .nextLong(
-                        FORCE_REFRESH_JITTER_SLEEP / 2,
-                        FORCE_REFRESH_JITTER_SLEEP + 1);
+                        jitter / 2,
+                        jitter + 1);
         // Make sure we are not waiting for the next refresh after an
         // exception.  If we are, sleep based on the retry delay of
         // the refresh to prevent a hard loop in attempting to refresh a

src/test/java/com/amazonaws/secretsmanager/caching/SecretCacheTest.java

@@ -83,6 +83,30 @@ public void secretCacheConstructorTest() {
         } catch (Exception e) {
         }
     }
+    
+    @Test
+    public void testForceRefreshJitterConfiguration() {
+        // Test default value
+        SecretCacheConfiguration config = new SecretCacheConfiguration();
+        Assert.assertEquals(config.getForceRefreshJitterMillis(), SecretCacheConfiguration.DEFAULT_FORCE_REFRESH_JITTER);
+        
+        // Test setting a custom value
+        long customJitter = 250L;
+        config.setForceRefreshJitterMillis(customJitter);
+        Assert.assertEquals(config.getForceRefreshJitterMillis(), customJitter);
+        
+        // Test zero is valid
+        config.setForceRefreshJitterMillis(0);
+        Assert.assertEquals(config.getForceRefreshJitterMillis(), 0);
+    }
+    
+    @Test(expectedExceptions = IllegalArgumentException.class, 
+          expectedExceptionsMessageRegExp = "Force refresh jitter must be greater than or equal to zero")
+    public void testForceRefreshJitterValidation() {
+        // Test that negative values throw an exception
+        SecretCacheConfiguration config = new SecretCacheConfiguration();
+        config.setForceRefreshJitterMillis(-1);
+    }
 
     @Test
     public void basicSecretCacheTest() {