Openfire Service active (exited)

Setup:
SO: Ubuntu 18.04
when I try to start the service:

● openfire.service - LSB: Start/stop openfire jabber server
** Loaded: loaded (/etc/init.d/openfire; generated)**
** Active: active (running) since Mon 2021-08-23 10:39:36 UTC; 5s ago**
** Docs: man:systemd-sysv-generator(8)**
** Process: 2708 ExecStop=/etc/init.d/openfire stop (code=exited, status=0/SUCCESS)**
** Process: 2728 ExecStart=/etc/init.d/openfire start (code=exited, status=0/SUCCESS)**
** Tasks: 15 (limit: 1105)**
** CGroup: /system.slice/openfire.service**
** └─2746 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java -server -DopenfireHome=/usr/share/openfire -Dlog4j.configurationFile=/usr/share/openfire/lib/log4j**

and to second later:

● openfire.service - LSB: Start/stop openfire jabber server
** Loaded: loaded (/etc/init.d/openfire; generated)**
** Active: active (exited) since Mon 2021-08-23 10:39:36 UTC; 9s ago**
** Docs: man:systemd-sysv-generator(8)**
** Process: 2708 ExecStop=/etc/init.d/openfire stop (code=exited, status=0/SUCCESS)**
** Process: 2728 ExecStart=/etc/init.d/openfire start (code=exited, status=0/SUCCESS)**

Aug 23 10:39:36 jabber.orbita.co.cu systemd[1]: Starting LSB: Start/stop openfire jabber server…
Aug 23 10:39:36 jabber.orbita.co.cu openfire[2728]: best java alternative in: /usr/lib/jvm/java-8-openjdk-amd64/jre
Aug 23 10:39:36 jabber.orbita.co.cu openfire[2728]: Starting openfire: openfire.
Aug 23 10:39:36 jabber.orbita.co.cu systemd[1]: Started LSB: Start/stop openfire jabber server.

tailf -f /var/log/openfire/error.log

at java.lang.reflect.Constructor.newInstance(Constructor.java:423) [?:1.8.0_292]
** at java.lang.Class.newInstance(Class.java:442) [?:1.8.0_292]**
** at org.jivesoftware.openfire.starter.ServerStarter.start(ServerStarter.java:92) [startup.jar:4.5.3]**
** at org.jivesoftware.openfire.starter.ServerStarter.main(ServerStarter.java:56) [startup.jar:4.5.3]**
Caused by: java.sql.SQLException: ConnectionManager.getConnection() failed to obtain a connection after 11 retries. The exception from the last attempt is as follows: com.mysql.cj.jdbc.exceptions.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 org.jivesoftware.database.DbConnectionManager.getConnection(DbConnectionManager.java:204) ~[xmppserver-4.5.3.jar:4.5.3]**
** at org.jivesoftware.openfire.XMPPServer.verifyDataSource(XMPPServer.java:1027) ~[xmppserver-4.5.3.jar:4.5.3]**
** … 9 more**

I don’t know what to do, thanks