keith-turner commented on code in PR #4551:
URL: https://github.com/apache/accumulo/pull/4551#discussion_r1597496346


##########
server/tserver/src/main/java/org/apache/accumulo/tserver/ScanServer.java:
##########
@@ -246,9 +246,30 @@ public ScanServer(ScanServerOpts opts, String[] args) {
         LOG.warn(
             "Tablet metadata caching less than one minute, may cause excessive 
scans on metadata table.");
       }
-      tabletMetadataCache =
-          Caffeine.newBuilder().expireAfterWrite(cacheExpiration, 
TimeUnit.MILLISECONDS)
-              
.scheduler(Scheduler.systemScheduler()).recordStats().build(tabletMetadataLoader);
+
+      // Get the cache refresh percentage property
+      // Value must be less than 100% as 100 or over would effectively disable 
it
+      double cacheRefreshPercentage =
+          
getConfiguration().getFraction(Property.SSERV_CACHED_TABLET_METADATA_REFRESH_PERCENT);
+      Preconditions.checkArgument(cacheRefreshPercentage < cacheExpiration,
+          "Tablet metadata cache refresh percentage is '%s' but must be less 
than 1",
+          cacheRefreshPercentage);
+
+      var builder = Caffeine.newBuilder().expireAfterWrite(cacheExpiration, 
TimeUnit.MILLISECONDS)
+          .scheduler(Scheduler.systemScheduler()).recordStats();
+      if (cacheRefreshPercentage > 0) {
+        // Compute the refresh time as a percentage of the expiration time
+        // Cache hits after this time, but before expiration, will trigger a 
background
+        // non-blocking refresh of the entry so future cache hits get an 
updated entry
+        // without having to block for a refresh
+        long cacheRefresh = (long) (cacheExpiration * cacheRefreshPercentage);
+        LOG.debug("Tablet metadata refresh percentage set to {}, refresh time 
set to {} ms",
+            cacheRefreshPercentage, cacheRefresh);
+        builder.refreshAfterWrite(cacheRefresh, TimeUnit.MILLISECONDS);

Review Comment:
   > It is usually good to configure the redirects in an application to ensure 
everything goes to your preferred logger (log4j2).
   
   Thanks for the tip @ben-manes.  Need to look into the default configs for 
Accumulo and see if any handling is being setup for jul->log4j2.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to