service doesn't start

2020-04-08 14:56:54  INFO: SELECT COUNT(*) FROM public.databasechangelog                                                                                                                                    
2020-04-08 14:56:54  INFO: Reading from public.databasechangelog                                                                                                                                            
2020-04-08 14:56:54  INFO: SELECT * FROM public.databasechangelog ORDER BY DATEEXECUTED ASC, ORDEREXECUTED ASC                                                                                              
2020-04-08 14:56:54  INFO: Successfully released change log lock   

It gets stuck here, it used to start after 20-30mins sometimes, but today it has just refused. I have restarted the server. Restarted the database service

Here is my service file ExecStart:

ExecStart=/opt/traccar/jre/bin/java -Djdk.tls.client.protocols=TLSv1.2 -Xms4096m -Xmx6144m -jar tracker-server.jar conf/traccar.xml

1. How big is your database?
2. Is it using SSD storage?
3. Have you checked system logs?

1. Database is 1.3TB
2. The storage is ssd
3. Nothing on systemlogs

Filesystem                         Size  Used Avail Use% Mounted on
udev                               4.9G     0  4.9G   0% /dev
tmpfs                              999M   18M  982M   2% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  1.3T  517G  710G  43% /
tmpfs                              4.9G   52K  4.9G   1% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              4.9G     0  4.9G   0% /sys/fs/cgroup
tmpfs                              4.9G     0  4.9G   0% /run/shm
/dev/loop0                          92M   92M     0 100% /snap/core/8689
/dev/sda2                          976M  145M  765M  16% /boot
tmpfs                              999M     0  999M   0% /run/user/1000
/dev/loop2                          94M   94M     0 100% /snap/core/8935

You should probably check database processes and see if anything takes too long.

Let me check that and revert. there are other database on the server but no issues.. I actually tried vacuuming the tc_positions table and got an error can that be the issue? Deleting some of the records, will try and vacuum again and update

Well, if you just remove all of the positions, it will almost definitely cause some issues. You need to keep the ones that are referenced from devices or clear those references as well.

delete from tc_positions where devicetime < '2020-03-01 00:00:00+00';
delete from tc_events  where servertime < '2020-03-01 00:00:00.000';
delete from tc_statistics where capturetime < '2020-03-01 00:00:00.000';

This is what am running at the moment.

if I went ahead and cleared all the lastPositionId on tc_devices will it automatically update with new values

Yes.

There was an issue with our tc_positions tables, during db restoration something much have corrupted it. It was not vacuuming.. On truncating the table things are now okay.