SOLR-12055: Enable async logging by default SOLR-12753: Async logging ring buffer and OOM error

(cherry picked from commit 0de3905)

solr/CHANGES.txt

@@ -16,6 +16,28 @@ In this release, there is an example Solr server including a bundled
 servlet container in the directory named "example".
 See the Solr tutorial at https://lucene.apache.org/solr/guide/solr-tutorial.html
 
+==================  9.0.0 ==================
+
+Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
+
+Versions of Major Components
+---------------------
+Apache Tika 1.19.1
+Carrot2 3.16.0
+Velocity 1.7 and Velocity Tools 2.0
+Apache ZooKeeper 3.4.13
+Jetty 9.4.14.v20181114
+
+Upgrade Notes
+----------------------
+
+* SOLR-12055 introduces async logging by default. There's a small window where log messages may be lost
+  in the event of some hard crash. Switch back to synchronous logging if this is unacceptable, see
+  see commeints in the log4j2 configuration files (log4j2.xml by default).
+
+New Features
+----------------------
+
 ==================  8.1.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
@@ -56,7 +78,6 @@ Bug Fixes
 
 Improvements
 ----------------------
-
 * SOLR-12999: Index replication could delete segments before downloading segments from master if there is not enough
   disk space (noble)
 
@@ -69,6 +90,15 @@ Other Changes
 
 * SOLR-13222: Improve logging in StreamingSolrClients (Peter Cseh via Kevin Risden)
 
+* SOLR-12055: Enable async logging by default. This change improves throughput for logging. This opens
+  up a small window where log messages could possibly be lost. If this is unacceptable, switching back to synchronous
+  logging can be done by changing the log4j2.xml file, no internal Solr code changed to make async logging the default.
+  (Erick Erickson)
+
+* SOLR-12753: Async logging ring buffer and OOM error. When very long messages are written (1M messages or so),
+  it can produce an OOM error. Log messages are truncated at 10K via configuration in the log4j2.xml files.
+
+
 ==================  8.0.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
@@ -243,7 +273,7 @@ Bug Fixes
   this issue reverts the default replica placement policy to the 'legacy' assignment policy that was the default until
   Solr 7.4. (Gus Heck, Andrzej Bialecki, Bram Van Dam, shalin)
 
-* SOLR-13255 : ClassCastException when URPs try to read a String field which returns a ByteArrayUtf8CharSequence . This is a regression
+* SOLR-13255 : ClasscastException when URPs try to read a String field which returns a ByteArrayUTF8CHarSequence . This is a regression
   in release 7.7 (noble)
 
 
@@ -309,21 +339,6 @@ Other Changes
 
 * SOLR-9515: Hadoop dependencies have been upgraded to Hadoop 3.2.0 from 2.7.2. (Mark Miller, Kevin Risden)
 
-==================  7.8.0 ==================
-
-Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
-
-Versions of Major Components
----------------------
-Apache Tika 1.19.1
-Carrot2 3.16.0
-Velocity 1.7 and Velocity Tools 2.0
-Apache ZooKeeper 3.4.13
-Jetty 9.4.14.v20181114
-
-
-(No Changes)
-
 ==================  7.7.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
@@ -719,6 +734,7 @@ Upgrade Notes
   an object style.  Although the object style makes more sense, this was an overlooked back-compat break; sorry.
 
 
+
 New Features
 ----------------------
 

solr/core/src/java/org/apache/solr/util/StartupLoggingUtils.java

@@ -126,6 +126,23 @@ public final class StartupLoggingUtils {
         + "Please consult your logging framework of choice on how to configure the appropriate logging.", msg);
   }
 
+  /**
+   * Perhaps odd to put in startup utils, but this is where the logging-init code is so it seems logical to put the
+   * shutdown here too.
+   *
+   * Tests are particularly sensitive to this call or the object release tracker will report "lmax.disruptor" not
+   * terminating when asynch logging (new default as of 8.1) is enabled.
+   *
+   *
+   */
+  @SuppressForbidden(reason = "Legitimate log4j2 access")
+  public static void shutdown() {
+    if (!isLog4jActive()) {
+      logNotSupported("Not running log4j2, could not call shutdown for async logging.");
+      return;
+    }
+    LogManager.shutdown(true);
+  }
   /**
    * Return a string representing the current static ROOT logging level
    * @return a string TRACE, DEBUG, WARN, ERROR or INFO representing current log level. Default is INFO

solr/core/src/test-files/log4j2.xml

@@ -15,26 +15,55 @@
   See the License for the specific language governing permissions and
   limitations under the License.
   -->
-
+<!-- Configuration for asynchronous logging -->
 <Configuration>
   <Appenders>
     <Console name="STDERR" target="SYSTEM_ERR">
       <PatternLayout>
         <Pattern>
-          %-4r %-5p (%t) [%X{node_name} %X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%n
+          %maxLen{%-4r %-5p (%t) [%X{node_name} %X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%notEmpty{
+          =>%ex{short}}}{10240}%n
         </Pattern>
       </PatternLayout>
     </Console>
   </Appenders>
   <Loggers>
-    <Logger name="org.apache.zookeeper" level="WARN"/>
+    <AsyncLogger name="org.apache.zookeeper" level="WARN"/>
-    <Logger name="org.apache.hadoop" level="WARN"/>
+    <AsyncLogger name="org.apache.hadoop" level="WARN"/>
-    <Logger name="org.apache.directory" level="WARN"/>
+    <AsyncLogger name="org.apache.directory" level="WARN"/>
-    <Logger name="org.apache.solr.hadoop" level="INFO"/>
+    <AsyncLogger name="org.apache.solr.hadoop" level="INFO"/>
     <Logger name="org.eclipse.jetty" level="INFO"/>
 
-    <Root level="INFO">
+    <AsyncRoot level="INFO">
       <AppenderRef ref="STDERR"/>
-    </Root>
+    </AsyncRoot>
   </Loggers>
 </Configuration>
+
+<!-- Configuration for synchronous logging
+     there _may_ be a very small window where log messages will not be flushed
+     to the log file on abnormal shutdown. If even this risk is unacceptable, use
+     the configuration below
+-->
+<!--Configuration>
+<Appenders>
+  <Console name="STDERR" target="SYSTEM_ERR">
+    <PatternLayout>
+      <Pattern>
+        %-4r %-5p (%t) [%X{node_name} %X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%n
+      </Pattern>
+    </PatternLayout>
+  </Console>
+</Appenders>
+<Loggers>
+  <Logger name="org.apache.zookeeper" level="WARN"/>
+  <Logger name="org.apache.hadoop" level="WARN"/>
+  <Logger name="org.apache.directory" level="WARN"/>
+  <Logger name="org.apache.solr.hadoop" level="INFO"/>
+  <Logger name="org.eclipse.jetty" level="INFO"/>
+
+  <Root level="INFO">
+    <AppenderRef ref="STDERR"/>
+  </Root>
+</Loggers>
+</Configuration-->

solr/core/src/test/org/apache/solr/cloud/rule/ImplicitSnitchTest.java

@@ -23,7 +23,6 @@ import java.util.HashMap;
 import java.util.Map;
 
 import com.google.common.collect.Sets;
-import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.TestRuleLimitSysouts;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrException;
@@ -41,7 +40,7 @@ import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.when;
 
 @TestRuleLimitSysouts.Limit(bytes=32000)
-public class ImplicitSnitchTest extends LuceneTestCase {
+public class ImplicitSnitchTest extends SolrTestCaseJ4 {
 
   private ImplicitSnitch snitch;
   private SnitchContext context;

solr/core/src/test/org/apache/solr/handler/RequestLoggingTest.java

@@ -17,6 +17,7 @@
 package org.apache.solr.handler;
 
 import java.io.StringWriter;
+import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -30,7 +31,9 @@ import org.apache.logging.log4j.core.config.LoggerConfig;
 import org.apache.logging.log4j.core.layout.PatternLayout;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.util.SuppressForbidden;
+import org.apache.solr.common.util.TimeSource;
 import org.apache.solr.core.SolrCore;
+import org.apache.solr.util.TimeOut;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -48,7 +51,6 @@ public class RequestLoggingTest extends SolrTestCaseJ4 {
   @Before
   public void setupAppender() {
     LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
-    LoggerConfig config = ctx.getConfiguration().getLoggerConfig("RequestLoggingTest");
 
     writer = new StringWriter();
     appender = WriterAppender.createAppender(
@@ -62,18 +64,18 @@ public class RequestLoggingTest extends SolrTestCaseJ4 {
   }
 
   @Test
-  public void testLogBeforeExecuteWithCoreLogger() {
+  public void testLogBeforeExecuteWithCoreLogger() throws InterruptedException {
     Logger logger = LogManager.getLogger(SolrCore.class);
     testLogBeforeExecute(logger);
   }
 
   @Test
-  public void testLogBeforeExecuteWithRequestLogger() {
+  public void testLogBeforeExecuteWithRequestLogger() throws InterruptedException {
     Logger logger = LogManager.getLogger("org.apache.solr.core.SolrCore.Request");
     testLogBeforeExecute(logger);
   }
 
-  public void testLogBeforeExecute(Logger logger) {
+  public void testLogBeforeExecute(Logger logger) throws InterruptedException {
     Level level = logger.getLevel();
 
     LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
@@ -85,9 +87,22 @@ public class RequestLoggingTest extends SolrTestCaseJ4 {
     try {
       assertQ(req("q", "*:*"));
 
-      String output = writer.toString();
+      TimeOut timeOut = new TimeOut(10, TimeUnit.SECONDS, TimeSource.NANO_TIME);
-      Matcher matcher = Pattern.compile("DEBUG.*q=\\*:\\*.*").matcher(output);
+      boolean found = false;
-      assertTrue(matcher.find());
+      Matcher matcher;
+      String pat = "DEBUG.*q=\\*:\\*.*";
+      String output = "";
+      Pattern pattern = Pattern.compile(pat);
+      do {
+        output = writer.toString();
+        matcher = pattern.matcher(output);
+        found = matcher.find();
+        if (found) {
+          break;
+        }
+        timeOut.sleep(10);
+      } while (timeOut.hasTimedOut() == false);
+      assertTrue("Did not find expected pattern: '" + pat + "' in output: '" + output + "'", found);
       final String group = matcher.group();
       final String msg = "Should not have post query information";
       assertFalse(msg, group.contains("hits"));

solr/core/src/test/org/apache/solr/logging/TestLogWatcher.java

@@ -16,65 +16,61 @@
  */
 package org.apache.solr.logging;
 
+import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrDocument;
 import org.apache.solr.common.SolrDocumentList;
+import org.apache.solr.common.util.TimeSource;
+import org.apache.solr.util.TimeOut;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.lang.invoke.MethodHandles;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import static org.junit.Assert.assertEquals;
+public class TestLogWatcher extends SolrTestCaseJ4 {
-import static org.junit.Assert.assertTrue;
-
-public class TestLogWatcher {
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
   private LogWatcherConfig config;
 
   @Before
-  public void setUp() {
+  public void before() {
-    config = new LogWatcherConfig(true, null, null, 50);
+    config = new LogWatcherConfig(true, null, "INFO", 1);
   }
 
+  // Create several log watchers and ensure that new messages go to the new watcher.
   @Test
-  public void testLog4jWatcher() {
+  public void testLog4jWatcher() throws InterruptedException {
-    LogWatcher watcher = LogWatcher.newRegisteredLogWatcher(config, null);
+    LogWatcher watcher = null;
+    int lim = random().nextInt(3) + 2;
+    for (int idx = 0; idx < lim; ++idx) {
+      String msg = "This is a test message: " + idx;
+      watcher = LogWatcher.newRegisteredLogWatcher(config, null);
 
-    assertEquals(watcher.getLastEvent(), -1);
+      // First ensure there's nothing in the new watcher.
+      assertEquals(-1, watcher.getLastEvent());
 
-    log.warn("This is a test message");
+      // Now log a message and ensure that the new watcher sees it.
+      log.warn(msg);
 
-    assertTrue(watcher.getLastEvent() > -1);
+      // Loop to give the logger time to process the async message and notify the new watcher.
-
+      TimeOut timeOut = new TimeOut(10, TimeUnit.SECONDS, TimeSource.NANO_TIME);
-    SolrDocumentList events = watcher.getHistory(-1, new AtomicBoolean());
+      boolean foundMsg = false;
-    assertEquals(events.size(), 1);
+      // In local testing this loop usually succeeds 1-2 tries.
-
+      do {
-    SolrDocument event = events.get(0);
+        // Returns an empty (but non-null) list even if there are no messages yet.
-    assertEquals(event.get("logger"), "org.apache.solr.logging.TestLogWatcher");
+        SolrDocumentList events = watcher.getHistory(-1, new AtomicBoolean());
-    assertEquals(event.get("message"), "This is a test message");
+        for (SolrDocument doc : events) {
+          if (doc.get("message").equals(msg)) {
+            foundMsg = true;
+            break;
+          }
+        }
+        Thread.sleep(10);
+      } while (timeOut.hasTimedOut() == false);
 
+      assertTrue("Should have found message " + msg + " in loop: " + idx, foundMsg);
+    }
   }
-
-  // This seems weird to do the same thing twice, this is valid. We need to test whether listeners are replaced....
-  @Test
-  public void testLog4jWatcherRepeat() {
-    LogWatcher watcher = LogWatcher.newRegisteredLogWatcher(config, null);
-
-    assertEquals(watcher.getLastEvent(), -1);
-
-    log.warn("This is a test message");
-
-    assertTrue(watcher.getLastEvent() > -1);
-
-    SolrDocumentList events = watcher.getHistory(-1, new AtomicBoolean());
-    assertEquals(events.size(), 1);
-
-    SolrDocument event = events.get(0);
-    assertEquals(event.get("logger"), "org.apache.solr.logging.TestLogWatcher");
-    assertEquals(event.get("message"), "This is a test message");
-
-  }
-
 }

solr/core/src/test/org/apache/solr/schema/UUIDFieldTest.java

@@ -16,10 +16,10 @@
  */
 package org.apache.solr.schema;
 
-import org.apache.lucene.util.LuceneTestCase;
+import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrException;
 
-public class UUIDFieldTest extends LuceneTestCase {
+public class UUIDFieldTest extends SolrTestCaseJ4 {
   public void testToInternal() {
     boolean ok = false;
     UUIDField uuidfield = new UUIDField();

solr/core/src/test/org/apache/solr/search/SignificantTermsQParserPluginTest.java

@@ -17,10 +17,10 @@
 
 package org.apache.solr.search;
 
-import org.apache.lucene.util.LuceneTestCase;
+import org.apache.solr.SolrTestCaseJ4;
 import org.junit.Test;
 
-public class SignificantTermsQParserPluginTest extends LuceneTestCase {
+public class SignificantTermsQParserPluginTest extends SolrTestCaseJ4 {
 
   /**
    * Test the backwards compatibility for a typo in the SignificantTermsQParserPlugin. It will fail if the backwards

solr/core/src/test/org/apache/solr/util/TestObjectReleaseTracker.java

@@ -16,7 +16,6 @@
  */
 package org.apache.solr.util;
 
-import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.TestRuleLimitSysouts.Limit;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.util.ObjectReleaseTracker;
@@ -24,7 +23,7 @@ import org.junit.Test;
 
 
 @Limit(bytes=150000) // raise limit as this writes to sys err
-public class TestObjectReleaseTracker extends LuceneTestCase {
+public class TestObjectReleaseTracker extends SolrTestCaseJ4 {
   
   @Test
   public void testObjectReleaseTracker() {

solr/core/src/test/org/apache/solr/util/TestSystemIdResolver.java

@@ -23,12 +23,11 @@ import java.util.Arrays;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.lucene.analysis.util.ResourceLoader;
-import org.apache.lucene.util.LuceneTestCase;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.core.SolrResourceLoader;
 import org.xml.sax.InputSource;
 
-public class TestSystemIdResolver extends LuceneTestCase {
+public class TestSystemIdResolver extends SolrTestCaseJ4 {
   
   public void tearDown() throws Exception {
     System.clearProperty("solr.allow.unsafe.resourceloading");

solr/server/resources/log4j2-console.xml

@@ -18,22 +18,50 @@
 
 <!-- Use this file for logging exlusively to the console, useful for 
      some development tasks. Should not be used for production -->
+<!-- Configuration for asynchronous logging -->
 <Configuration>
   <Appenders>
     <Console name="STDERR" target="SYSTEM_ERR">
       <PatternLayout>
         <Pattern>
-          %-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %c; %m%n
+          %maxLen{%-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %c; %m%notEmpty{ =>%ex{short}}}{10240}%n
         </Pattern>
       </PatternLayout>
     </Console>
   </Appenders>
   <Loggers>
-    <Logger name="org.apache.zookeeper" level="WARN"/>
+    <AsyncLogger name="org.apache.zookeeper" level="WARN"/>
-    <Logger name="org.apache.hadoop" level="WARN"/>
+    <AsyncLogger name="org.apache.hadoop" level="WARN"/>
 
-    <Root level="INFO">
+    <AsyncRoot level="INFO">
       <AppenderRef ref="STDERR"/>
-    </Root>
+    </AsyncRoot>
   </Loggers>
 </Configuration>
+
+
+<!-- Configuration for synchronous logging
+     there _may_ be a very small window where log messages will not be flushed
+     to the log file on abnormal shutdown. If even this risk is unacceptable, use
+     the configuration below
+-->
+<!--Configuration>
+<Appenders>
+  <Console name="STDERR" target="SYSTEM_ERR">
+    <PatternLayout>
+      <Pattern>
+        %-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %c; %m%n
+      </Pattern>
+    </PatternLayout>
+  </Console>
+</Appenders>
+<Loggers>
+  <Logger name="org.apache.zookeeper" level="WARN"/>
+  <Logger name="org.apache.hadoop" level="WARN"/>
+
+  <Root level="INFO">
+    <AppenderRef ref="STDERR"/>
+  </Root>
+</Loggers>
+</Configuration-->
+

solr/server/resources/log4j2.xml

@@ -16,7 +16,72 @@
   limitations under the License.
   -->
 
+<!-- Configuration for asynchronous logging -->
 <Configuration>
+  <Appenders>
+
+    <Console name="STDOUT" target="SYSTEM_OUT">
+      <PatternLayout>
+        <Pattern>
+          %maxLen{%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p (%t) [%X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%notEmpty{ =>%ex{short}}}{10240}%n
+        </Pattern>
+      </PatternLayout>
+    </Console>
+
+    <RollingRandomAccessFile
+        name="MainLogFile"
+        fileName="${sys:solr.log.dir}/solr.log"
+        filePattern="${sys:solr.log.dir}/solr.log.%i" >
+      <PatternLayout>
+        <Pattern>
+          %maxLen{%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p (%t) [%X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%notEmpty{ =>%ex{short}}}{10240}%n
+        </Pattern>
+      </PatternLayout>
+      <Policies>
+        <OnStartupTriggeringPolicy />
+        <SizeBasedTriggeringPolicy size="32 MB"/>
+      </Policies>
+      <DefaultRolloverStrategy max="10"/>
+    </RollingRandomAccessFile>
+
+    <RollingRandomAccessFile
+        name="SlowLogFile"
+        fileName="${sys:solr.log.dir}/solr_slow_requests.log"
+        filePattern="${sys:solr.log.dir}/solr_slow_requests.log.%i" >
+      <PatternLayout>
+        <Pattern>
+          %maxLen{%d{yyyy-MM-dd HH:mm:ss.SSS} %-5p (%t) [%X{collection} %X{shard} %X{replica} %X{core}] %c{1.} %m%notEmpty{ =>%ex{short}}}{10240}%n
+        </Pattern>
+      </PatternLayout>
+      <Policies>
+        <OnStartupTriggeringPolicy />
+        <SizeBasedTriggeringPolicy size="32 MB"/>
+      </Policies>
+      <DefaultRolloverStrategy max="10"/>
+    </RollingRandomAccessFile>
+
+  </Appenders>
+  <Loggers>
+    <AsyncLogger name="org.apache.hadoop" level="warn"/>
+    <AsyncLogger name="org.apache.solr.update.LoggingInfoStream" level="off"/>
+    <AsyncLogger name="org.apache.zookeeper" level="warn"/>
+    <AsyncLogger name="org.apache.solr.core.SolrCore.SlowRequest" level="info" additivity="false">
+      <AppenderRef ref="SlowLogFile"/>
+    </AsyncLogger>
+
+    <AsyncRoot level="info">
+      <AppenderRef ref="MainLogFile"/>
+      <AppenderRef ref="STDOUT"/>
+    </AsyncRoot>
+  </Loggers>
+</Configuration>
+
+<!-- Configuration for synchronous logging
+     there _may_ be a very small window where log messages will not be flushed
+     to the log file on abnormal shutdown. If even this risk is unacceptable, use
+     the configuration below
+-->
+<!--Configuration>
   <Appenders>
 
     <Console name="STDOUT" target="SYSTEM_OUT">
@@ -73,4 +138,5 @@
       <AppenderRef ref="STDOUT"/>
     </Root>
   </Loggers>
-</Configuration>
+</Configuration-->
+

solr/solr-ref-guide/src/solr-upgrade-notes.adoc

@@ -26,6 +26,16 @@ When planning your Solr upgrade, consider the customizations you have made to yo
 
 Detailed steps for upgrading a Solr cluster are in the section <<upgrading-a-solr-cluster.adoc#upgrading-a-solr-cluster,Upgrading a Solr Cluster>>.
 
+== Upgrading to 8.x Releases
+
+=== Solr 8.1
+
+*Logging*
+
+Solr 8.1 changed the default log4j2 logging mode from synchronous to asynchronous. This will improve logging throughput and reduce system contention at the cost of a _slight_ chance that some logging messages may be missed in the event of abnormal Solr termination.
+
+If even this slight risk is unacceptable, the log4j configuration file ../server/resources/log4j2.xml has the synchronous logging configuration in a commented section and can be edited to re-enable synchronous logging.
+
 == Upgrading to 7.x Releases
 
 === Solr 7.6

solr/test-framework/src/java/org/apache/solr/SolrTestCaseJ4.java

@@ -348,6 +348,8 @@ public abstract class SolrTestCaseJ4 extends LuceneTestCase {
       sslConfig = null;
       testSolrHome = null;
 
+      StartupLoggingUtils.shutdown();
+
       IpTables.unblockAllPorts();
 
       LogLevel.Configurer.restoreLogLevels(savedClassLogLevels);