From 53a9710ec87f74649acedd3e6a39ada11e51e9d2 Mon Sep 17 00:00:00 2001
From: anhefti <andreas.hefti@let.ethz.ch>
Date: Thu, 4 Mar 2021 13:48:16 +0100
Subject: [PATCH] Improved event log batch processing

---
 .../session/impl/AsyncBatchEventSaveStrategy.java        | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/AsyncBatchEventSaveStrategy.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/AsyncBatchEventSaveStrategy.java
index eceb62d6..d1936134 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/AsyncBatchEventSaveStrategy.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/AsyncBatchEventSaveStrategy.java
@@ -59,6 +59,9 @@ public class AsyncBatchEventSaveStrategy implements EventHandlingStrategy {
 
     private static final int NUMBER_OF_WORKER_THREADS = 4;
     private static final int BATCH_SIZE = 100;
+    private static final int MIN_SLEEP_TIME = 100;
+    private static final int SLEEP_TIME_EXPAND = 100;
+    private static final int MAX_SLEEP_TIME = 5000;
 
     private final SqlSessionFactory sqlSessionFactory;
     private final Executor executor;
@@ -150,7 +153,7 @@ public class AsyncBatchEventSaveStrategy implements EventHandlingStrategy {
 
                     try {
                         if (!events.isEmpty()) {
-                            sleepTime = 100;
+                            sleepTime = MIN_SLEEP_TIME;
                             this.transactionTemplate
                                     .execute(status -> {
                                         events.forEach(clientEventMapper::insert);
@@ -158,8 +161,8 @@ public class AsyncBatchEventSaveStrategy implements EventHandlingStrategy {
                                     });
 
                             sqlSessionTemplate.flushStatements();
-                        } else {
-                            sleepTime += 100;
+                        } else if (sleepTime < MAX_SLEEP_TIME) {
+                            sleepTime += SLEEP_TIME_EXPAND;
                         }
                     } catch (final Exception e) {
                         log.error("unexpected Error while trying to batch store client-events: ", e);