HBASE-23956 Use less resources running tests (#1266)

Addendum: This test was depending on hard-coded number for
log cleaners; the parent patch made them less in test context.

Author: saintstack

hbase-server/src/test/java/org/apache/hadoop/hbase/master/cleaner/TestLogsCleaner.java

@@ -298,7 +298,7 @@ public void testOnConfigurationChange() throws Exception {
 
     FileSystem fs = TEST_UTIL.getDFSCluster().getFileSystem();
     LogCleaner cleaner = new LogCleaner(3000, server, conf, fs, OLD_WALS_DIR, POOL);
-    assertEquals(LogCleaner.DEFAULT_OLD_WALS_CLEANER_THREAD_SIZE, cleaner.getSizeOfCleaners());
+    int size = cleaner.getSizeOfCleaners();
     assertEquals(LogCleaner.DEFAULT_OLD_WALS_CLEANER_THREAD_TIMEOUT_MSEC,
         cleaner.getCleanerThreadTimeoutMsec());
     // Create dir and files for test
@@ -313,10 +313,10 @@ public void testOnConfigurationChange() throws Exception {
     // change size of cleaners dynamically
     int sizeToChange = 4;
     long threadTimeoutToChange = 30 * 1000L;
-    conf.setInt(LogCleaner.OLD_WALS_CLEANER_THREAD_SIZE, sizeToChange);
+    conf.setInt(LogCleaner.OLD_WALS_CLEANER_THREAD_SIZE, size + sizeToChange);
     conf.setLong(LogCleaner.OLD_WALS_CLEANER_THREAD_TIMEOUT_MSEC, threadTimeoutToChange);
     cleaner.onConfigurationChange(conf);
-    assertEquals(sizeToChange, cleaner.getSizeOfCleaners());
+    assertEquals(sizeToChange + size, cleaner.getSizeOfCleaners());
     assertEquals(threadTimeoutToChange, cleaner.getCleanerThreadTimeoutMsec());
     // Stop chore
     thread.join();