Fix intermittent failure in examples. Format code

examples/pom.xml

@@ -11,7 +11,7 @@
     <dependency>
       <groupId>com.yugabyte</groupId>
       <artifactId>jdbc-yugabytedb</artifactId>
-      <version>42.3.5-yb-4-SNAPSHOT</version>
+      <version>42.3.5-yb-5-SNAPSHOT</version>
     </dependency>
 
     <!-- https://mvnrepository.com/artifact/com.zaxxer/HikariCP -->

examples/run.sh

@@ -83,7 +83,7 @@ echo "Choose one of the below options"
 echo "1. Demonstrate Uniform Load Balance"
 echo "2. Demonstrate Topology Aware Load Balance"
 echo "3. Demonstrate Fallback feature of Topology Aware Load Balance"
-read -p "Please enter your option and then press enter:" choice
+read -p "Please enter your option and then press enter: " choice
 echo ""
 
 case $choice in

examples/src/main/java/com/yugabyte/examples/UniformLoadBalanceExample.java

@@ -42,12 +42,11 @@ public static void main(String[] args) {
     String controlHost = "127.0.0.1";
     String controlPort = "5433";
 
+    controlUrl = "jdbc:yugabytedb://" + controlHost + ":" + controlPort
+        + "/yugabyte?user=yugabyte&password=yugabyte&load-balance=true"
+        + "&yb-servers-refresh-interval=0";
     if (debugLogging) {
-      controlUrl = "jdbc:yugabytedb://" + controlHost
-        + ":" + controlPort + "/yugabyte?user=yugabyte&password=yugabyte&load-balance=true&loggerLevel=debug&yb-servers-refresh-interval=0";
-    } else {
-      controlUrl = "jdbc:yugabytedb://" + controlHost
-        + ":" + controlPort + "/yugabyte?user=yugabyte&password=yugabyte&load-balance=true&yb-servers-refresh-interval=0";
+      controlUrl = controlUrl + "&loggerLevel=debug";
     }
 
     System.out.println("Setting up the connection pool having 6 connections.......");
@@ -83,6 +82,7 @@ protected static void testUsingHikariPool(String poolName, String lbpropvalue, S
       if (!lbpropvalue.equals("true")) {
         poolProperties.setProperty("dataSource.topologyKeys", lookupKey);
       }
+      poolProperties.setProperty("dataSource.ybServersRefreshInterval", "0");
 
       HikariConfig hikariConfig = new HikariConfig(poolProperties);
       hikariConfig.validate();

examples/uniform_load_balance_run.sh

@@ -1,4 +1,4 @@
-#!/bin/bash                                                
+#!/bin/bash
 
 # Copyright (c) YugaByte, Inc.
 #
@@ -41,15 +41,15 @@ finish() {
   kill -9 $2 >> yb-ctl.log 2>&1
 
   #deleting the temporary files
-  rm -rf .jdbc_example_app_checker  
+  rm -rf .jdbc_example_app_checker
   rm -rf .jdbc_example_app_checker2
-  rm -rf .jdbc_example_app_checker3 
+  rm -rf .jdbc_example_app_checker3
   rm -rf .notify_shell_script
 }
 
 #this function basically checks the $file content and keep it paused until required content is present
 pauseScript() {
-  #just creating the file if it doesn't exsits
+  #just creating the file if it doesn't exist
   file=.notify_shell_script
   touch $file
 
@@ -80,11 +80,11 @@ $INSTALL_DIR/bin/yb-ctl destroy  > yb-ctl.log 2>&1
 
 echo "Creating a 3-node, RF-3 cluster (live nodes: 1,2,3)"
 $INSTALL_DIR/bin/yb-ctl create --rf 3  >> yb-ctl.log 2>&1
-
+SLEEP 5
 
 #deleting the checker file if exists
 verbosePrint $VERBOSE "Deleting all the temporary checker files if exists"
-rm -rf .jdbc_example_app_checker  
+rm -rf .jdbc_example_app_checker
 rm -rf .jdbc_example_app_checker2
 rm -rf .jdbc_example_app_checker3 #to keep the java app running until killed
 rm -rf .notify_shell_script
@@ -106,6 +106,7 @@ interact $INTERACTIVE
 
 echoSleep "Adding Node-4 to the cluster (live nodes: 1,2,3,4)"
 $INSTALL_DIR/bin/yb-ctl add_node >> yb-ctl.log 2>&1
+SLEEP 5
 
 touch .jdbc_example_app_checker   #resuming the java app
 

pgjdbc/src/main/java/com/yugabyte/ysql/ClusterAwareLoadBalancer.java

@@ -41,8 +41,10 @@ public static ClusterAwareLoadBalancer getInstance(int refreshListSeconds) {
         if (instance == null) {
           instance = new ClusterAwareLoadBalancer();
           instance.refreshListSeconds =
-              refreshListSeconds > 0 && refreshListSeconds <= LoadBalanceProperties.MAX_REFRESH_INTERVAL ?
+              refreshListSeconds >= 0 && refreshListSeconds <= LoadBalanceProperties.MAX_REFRESH_INTERVAL ?
                   refreshListSeconds : LoadBalanceProperties.DEFAULT_REFRESH_INTERVAL;
+          LOGGER.fine("Created a new cluster-aware LB instance with refresh" +
+              " interval " + instance.refreshListSeconds + " seconds");
         }
       }
     }

pgjdbc/src/main/java/com/yugabyte/ysql/LoadBalanceProperties.java

@@ -133,11 +133,16 @@ public String processURLAndProperties() {
           try {
             refreshInterval = Integer.parseInt(lbParts[1]);
             if (refreshInterval < 0 || refreshInterval > MAX_REFRESH_INTERVAL) {
+              LOGGER.warning("Provided yb-servers-refresh-interval ("
+                  + refreshInterval + ") is outside the permissible range,"
+                  + " setting it to 300 seconds");
               refreshInterval = DEFAULT_REFRESH_INTERVAL;
             } else {
               refreshIntervalSpecified = true;
             }
           } catch (NumberFormatException nfe) {
+            LOGGER.warning("Provided yb-servers-refresh-interval ("
+                + refreshInterval + ") is invalid, setting it to 300 seconds");
             refreshInterval = DEFAULT_REFRESH_INTERVAL;
           }
         } else if (part.startsWith(explicitFallbackOnlyKey)) {
@@ -194,11 +199,16 @@ public String processURLAndProperties() {
         try {
           refreshInterval = Integer.parseInt(propValue);
           if (refreshInterval < 0 || refreshInterval > MAX_REFRESH_INTERVAL) {
+            LOGGER.warning("Provided yb-servers-refresh-interval ("
+                + refreshInterval + ") is outside the permissible range,"
+                + " setting it to 300 seconds");
             refreshInterval = DEFAULT_REFRESH_INTERVAL;
           } else {
             refreshIntervalSpecified = true;
           }
         } catch (NumberFormatException nfe) {
+          LOGGER.warning("Provided yb-servers-refresh-interval ("
+              + refreshInterval + ") is invalid, setting it to 300 seconds");
           refreshInterval = DEFAULT_REFRESH_INTERVAL;
         }
       }

pgjdbc/src/main/java/com/yugabyte/ysql/YBClusterAwareDataSource.java

@@ -44,4 +44,8 @@ public void setAdditionalEndpoints(String value) {
   public String getAdditionalEndPoints() {
     return additionalEndPoints;
   }
+
+  public String getDescription() {
+    return "YB cluster-aware DataSource from YugabyteDB JDBC Driver (YSQL)";
+  }
 }