Good morning.The problem is that my tomcat container having my war file(spring boot app) in webapps folder is not connecting with my mysql container in kubernetes.

When I checked logs of tomcat pod it says unknown host expection:mysql and jdbc communication link failure.

application.properties file present in war file

# Set here configurations for the database connection
# Connection url for the database "account-database"
spring.datasource.url = jdbc:mysql://${MYSQL_DB_HOST}:${MYSQL_DB_PORT}/data-core?allowPublicKeyRetrieval=true
spring.datasource.url1 = jdbc:mysql://${MYSQL_DB_HOST}:${MYSQL_DB_PORT}/data-core
# Username and password
spring.datasource.username = ${MYSQL_DB_USER}
spring.datasource.password = ${MYSQL_DB_PASSWORD}

# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1

spring.datasource.tomcat.max-wait=360000

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://${MYSQL_DB_HOST}:${MYSQL_DB_PORT}/data-core
username=${MYSQL_DB_USER}
password=${MYSQL_DB_PASSWORD}
app.domain=com.wootz.works

mysql.yaml

apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:

  ports:
  - port: 3306
    protocol: TCP
    targetPort: 3306


  selector:
    app: mysql

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        imagePullPolicy: "IfNotPresent"
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: root
        - name: MYSQL_PASSWORD
          value: kovaion
        - name: MYSQL_USER
          value: vignesh
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /docker-entrypoint-initdb.d
      volumes:
      - name: mysql-persistent-storage
        persistentVolumeClaim:
          claimName: mysql-initdb-pv-claim

tomcat.yaml

apiVersion: v1
kind: Service
metadata:
  name: tomcat
  labels:
    app: tomcat
spec:
  type: NodePort
  ports:
  - name: myport
    port: 8080
    targetPort: 8080
    nodePort: 30000
  selector:
    app: tomcat
    tier: frontend

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat
  labels:
    app: tomcat
spec:
  selector:
    matchLabels:
      app: tomcat
      tier: frontend
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: tomcat
        tier: frontend
    spec:

      containers:
      - image: suji165475/vignesh:try
        name: tomcat
        env:
        - name: MYSQL_DB_USER
          value: vignesh
        - name: MYSQL_DB_PASSWORD
          value: kovaion
        - name: MYSQL_DB_HOST
          value: mysql
        - name: MYSQL_DB_PORT
          value: "3306"
        - name: MYSQL_ROOT_PASSWORD
          value: root
        ports:
        - containerPort: 8080
          name: myport

        volumeMounts:
        - name: tomcat-persistent-storage
          mountPath: /var/data
      volumes:
      - name: tomcat-persistent-storage
        persistentVolumeClaim:
        claimName: tomcat-pv-claim

catalina.logs

May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version:        Apache Tomcat/7.0.86
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Apr 9 2018 20:16:54 UTC
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         7.0.86.0
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Linux
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            4.15.0-47-generic
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             /usr/lib/jvm/java-8-openjdk-amd64/jre
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.8.0_162-8u162-b12-1~deb9u1-b12
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         /usr/local/tomcat
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         /usr/local/tomcat
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.config.file=/usr/local/tomcat/conf/logging.properties
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djdk.tls.ephemeralDHKeySize=2048
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dignore.endorsed.dirs=
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=/usr/local/tomcat
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=/usr/local/tomcat
May 13, 2019 1:56:16 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.io.tmpdir=/usr/local/tomcat/temp
May 13, 2019 1:56:16 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: Loaded APR based Apache Tomcat Native library 1.2.16 using APR version 1.5.2.
May 13, 2019 1:56:16 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
May 13, 2019 1:56:16 PM org.apache.catalina.core.AprLifecycleListener initializeSSL
INFO: OpenSSL successfully initialized (OpenSSL 1.1.0f  25 May 2017)
May 13, 2019 1:56:16 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-apr-8080"]
May 13, 2019 1:56:16 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-apr-8009"]
May 13, 2019 1:56:16 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1039 ms
May 13, 2019 1:56:16 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
May 13, 2019 1:56:16 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.86
May 13, 2019 1:56:16 PM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /usr/local/tomcat/webapps/data-core-0.0.1-SNAPSHOT.war
May 13, 2019 1:56:21 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
May 13, 2019 1:56:47 PM org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/data-core-0.0.1-SNAPSHOT]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1017)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:993)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1127)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:2020)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.tool.schema.spi.SchemaManagementException: Unable to open JDBC connection for schema management target
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1630)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:481)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1082)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:124)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    at org.springframework.boot.web.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:156)
    at org.springframework.boot.web.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:136)
    at org.springframework.boot.web.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91)
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:169)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5653)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    ... 10 more
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.tool.schema.spi.SchemaManagementException: Unable to open JDBC connection for schema management target
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:396)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1688)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1626)
    ... 29 more
Caused by: org.hibernate.tool.schema.spi.SchemaManagementException: Unable to open JDBC connection for schema management target
    at org.hibernate.tool.schema.internal.TargetDatabaseImpl.prepare(TargetDatabaseImpl.java:42)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.doMigration(SchemaMigratorImpl.java:57)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:134)
    at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:101)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:472)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879)
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:384)
    ... 33 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:342)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2197)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2230)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2025)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:778)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:319)
    at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:212)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:736)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:668)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:483)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
    at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131)
    at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
    at org.hibernate.tool.schema.internal.TargetDatabaseImpl.prepare(TargetDatabaseImpl.java:38)
    ... 42 more
Caused by: java.net.UnknownHostException: mysql
    at java.net.InetAddress.getAllByName0(InetAddress.java:1280)
    at java.net.InetAddress.getAllByName(InetAddress.java:1192)
    at java.net.InetAddress.getAllByName(InetAddress.java:1126)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:188)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:301)
    ... 66 more

May 13, 2019 1:56:47 PM org.apache.catalina.startup.HostConfig deployWAR
SEVERE: Error deploying web application archive /usr/local/tomcat/webapps/data-core-0.0.1-SNAPSHOT.war
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/data-core-0.0.1-SNAPSHOT]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1021)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:993)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1127)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:2020)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

May 13, 2019 1:56:47 PM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deployment of web application archive /usr/local/tomcat/webapps/data-core-0.0.1-SNAPSHOT.war has finished in 30,777 ms
May 13, 2019 1:56:47 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /usr/local/tomcat/webapps/examples
May 13, 2019 1:56:47 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /usr/local/tomcat/webapps/examples has finished in 290 ms
May 13, 2019 1:56:47 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /usr/local/tomcat/webapps/manager
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /usr/local/tomcat/webapps/manager has finished in 110 ms
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /usr/local/tomcat/webapps/ROOT
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /usr/local/tomcat/webapps/ROOT has finished in 36 ms
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /usr/local/tomcat/webapps/host-manager
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /usr/local/tomcat/webapps/host-manager has finished in 39 ms
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /usr/local/tomcat/webapps/docs
May 13, 2019 1:56:48 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /usr/local/tomcat/webapps/docs has finished in 29 ms
May 13, 2019 1:56:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-apr-8080"]
May 13, 2019 1:56:48 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-apr-8009"]
May 13, 2019 1:56:48 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 31367 ms
May 13, 2019 1:57:55 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
May 13, 2019 1:57:55 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
May 13, 2019 1:57:56 PM org.apache.catalina.loader.WebappClassLoaderBase findResourceInternal
INFO: Illegal access: this web application instance has been stopped already.  Could not load .  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
May 13, 2019 1:57:58 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
May 13, 2019 1:58:49 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
May 13, 2019 1:58:49 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
May 13, 2019 1:58:51 PM org.apache.catalina.loader.WebappClassLoaderBase findResourceInternal
INFO: Illegal access: this web application instance has been stopped already.  Could not load .  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
May 13, 2019 1:58:52 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
May 13, 2019 1:59:23 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
May 13, 2019 1:59:23 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
May 13, 2019 1:59:25 PM org.apache.catalina.loader.WebappClassLoaderBase findResourceInternal
INFO: Illegal access: this web application instance has been stopped already.  Could not load .  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
May 13, 2019 1:59:26 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
May 13, 2019 2:07:52 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
May 13, 2019 2:07:52 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
SEVERE: The web application [/data-core-0.0.1-SNAPSHOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
May 13, 2019 2:07:55 PM org.apache.catalina.loader.WebappClassLoaderBase findResourceInternal
INFO: Illegal access: this web application instance has been stopped already.  Could not load .  The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
May 13, 2019 2:07:55 PM org.apache.catalina.startup.TldConfig execute
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

init.sql

CREATE DATABASE `data-core` /*!40100 DEFAULT CHARACTER SET latin1 */;
USE `data-core`;
CREATE TABLE `customer` (
`cust_id` varchar(255) NOT NULL,
`address1` varchar(255) DEFAULT NULL,
`address2` varchar(255) DEFAULT NULL,
`address3` varchar(255) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`phone` varchar(255) DEFAULT NULL,
PRIMARY KEY (`cust_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

CREATE TABLE `employee` (
`employee_id` varchar(255) NOT NULL,
`emp_firstname` varchar(255) DEFAULT NULL,
`emp_lastname` varchar(255) DEFAULT NULL,
PRIMARY KEY (`employee_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE `project` (
`project_id` varchar(255) NOT NULL,
`cust_id` varchar(255) DEFAULT NULL,
`name` varchar(255) DEFAULT NULL,
`descr` varchar(255) DEFAULT NULL,
`status` varchar(255) DEFAULT NULL,
`total_po_value` double DEFAULT NULL,
`currency_cd` varchar(255) DEFAULT NULL,
`bill_schedule` varchar(255) DEFAULT NULL,
`bill_unit` varchar(255) DEFAULT NULL,
`cust_order_id` varchar(255) DEFAULT NULL,
`order_issue_dt` date DEFAULT NULL,
`order_start_dt` date DEFAULT NULL,
`order_end_dt` date DEFAULT NULL,
`owner` varchar(255) DEFAULT NULL,
`project_mode` varchar(255) DEFAULT NULL,
`addtl_info1` varchar(255) DEFAULT NULL,
`addtl_info2` varchar(255) DEFAULT NULL,
`addtl_info3` varchar(255) DEFAULT NULL,
`addtl_info4` varchar(255) DEFAULT NULL,
`employee_id` varchar(255) DEFAULT NULL,
`start_dt` date DEFAULT NULL,
`end_dt` date DEFAULT NULL,
PRIMARY KEY (`project_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

insert into `customer`(`cust_id`,`address1`,`address2`,`address3`,`email`,`name`,`phone`) values ('COMP001','#1-3-23/2 Street No  4','Hyderabad','Hyderabad 500 007','bbb@gmail.com','Sri Associates Pvt. Ltd','91 9949353238'),('comp002',null,null,null,'aaa@gmail.com','AAruth Private Limited',NULL),('COMP003',NULL,NULL,NULL,NULL,'TECH Infotech',NULL);

insert into `employee`(`employee_id`,`emp_firstname`,`emp_lastname`) values ('KOV01','TEST','TEST'),('KOV02','FIRST_NAME_TEST','LASTNAME_TEST'),('KOV03','THREE_F','THREE_L');

Note: when I try to ping mysql from tomcat container i get unknown host mysql.

currently I can see the tomcat homepage buy i cannot start the war file in tomcats manager app.I suspect this is due to tomcat not being able to connect to mysql container.Please help.