If you have ComicRack you can use this guide to use CR + it's extension that will scrape metadata from ComicVine and add it to your files:
https://vaemendis.github.io/ubooquity-doc/pages/tutorials/add-metadata-with-comicrack.html

My workflow looks something like this:

• Download comics
• Rename and move to appropriate directories on disk (i.e. my ubooquity comics library)
• use CR to look for new files in the specified library
• convert any .cbr to .cbz (i think since CBR is a .rar format there are issues with being able to write data to that format since it's not open source)
• use the ComicVineScraper extension in CR to scrape and add metadata to any unscraped files
• read and enjoy via opds feed on my android tablet from ubooquity to kuboo app

i currently use Comicrack to manage my library, convert to .cbz format, and embed metadata via the comicvine scraper. I use Ubooquity and Kuboo to serve and consume the library.

I followed the steps in this guide to integrate everything:

https://ubooquity.userecho.com/communities/1/topics/59-comicrack-database-integration

i was only running a single instance. Whenever I had to restart my box or if Ubooquity crashed I would get the"already in use" error message even though no instance of Ubooquity was running.

I found that if I get that error and I kill the entire java process I can get it to start cleanly again.

in Ubuntu I just killed the java process and then ran my start command again

sudo pkill -9 java

sudo nohup java - jar Ubooquity.jar

I think Ubooquity was not exiting cleanly. After I stopped the process or it crashed itself, the ports were still showing as being in use. I was able to kill the java processes tying up the ports in question and now I can load run the program again.

I'm only running a single instance of Ubooquity on ports 2204 and 2025.

I tried backing everything up in a separate folder and just starting with a fresh Ubooquity.jar from the website. Getting a different error now:

20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Running with the following parameters - headless: true, libraryport: 2204, adminport: 2205, remoteadmin: true, host: null, debug: false, execdir: /opt/ubooquity
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - #############################
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - # Starting Ubooquity #
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - #############################
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Java version: 1.8.0_242
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Java vendor: Private Build
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - java vm name: OpenJDK 64-Bit Server VM
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - java runtime name: OpenJDK Runtime Environment
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Max heap size available: 7125 MB
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - OS name: Linux
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - OS version: 5.3.0-40-generic
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - OS architecture: amd64
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Loading local version info
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Ubooquity 2.1.2 built on 2018-10-14 at 12:58
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Creating application folders
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Loading preferences
20200318 14:45:40 [main] INFO com.ubooquity.Ubooquity - Saving preferences
20200318 14:45:41 [main] INFO org.eclipse.jetty.util.log - Logging initialized @1765ms to org.eclipse.jetty.util.log.Slf4jLog
20200318 14:45:41 [main] INFO com.ubooquity.b - Starting internal server...
20200318 14:45:41 [main] INFO com.ubooquity.b - Reverse proxy prefix is not activated
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Scanning books directories
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Finished scanning books directories, populating folders content cache
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Books folder content cache populated
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Scanning comics directories
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Finished scanning comics directories, populating folders content cache
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Comics folder content cache populated
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Comics statistics: [total: 0, added or updated: 0, removed: 0]
20200318 14:45:41 [Scanner thread] INFO com.ubooquity.data.feeder.a - Books statistics: [total: 0, added or updated: 0, removed: 0]
20200318 14:45:41 [main] INFO org.eclipse.jetty.server.Server - jetty-9.4.0.v20161208
20200318 14:45:41 [main] INFO o.e.j.server.handler.ContextHandler - Started o.e.j.s.h.ContextHandler@536f2a7e{/,null,AVAILABLE,@admin}
20200318 14:45:41 [main] INFO o.e.j.server.handler.ContextHandler - Started o.e.j.s.h.ContextHandler@72bc6553{/,null,AVAILABLE,@library}
20200318 14:45:41 [main] ERROR com.ubooquity.Ubooquity - Exiting application because of exception
org.eclipse.jetty.util.MultiException: Multiple exceptions
at org.eclipse.jetty.server.Server.doStart(Server.java:416) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) ~[jetty-util-9.4.0.v20161208.jar.8141124450067202531.tmp:9.4.0.v20161208]
at com.ubooquity.d.e.a(SourceFile:90) ~[Ubooquity.jar:2.1.2]
at com.ubooquity.b.a(SourceFile:95) ~[Ubooquity.jar:2.1.2]
at com.ubooquity.Ubooquity.main(SourceFile:222) ~[Ubooquity.jar:2.1.2]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_242]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_242]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_242]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_242]
at com.ubooquity.e.a.a(SourceFile:823) [Ubooquity.jar:2.1.2]
at com.ubooquity.Launcher.main(SourceFile:10) [Ubooquity.jar:2.1.2]
Suppressed: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method) ~[na:1.8.0_242]
at sun.nio.ch.Net.bind(Net.java:433) ~[na:1.8.0_242]
at sun.nio.ch.Net.bind(Net.java:425) ~[na:1.8.0_242]
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:220) ~[na:1.8.0_242]
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:85) ~[na:1.8.0_242]
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:298) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) ~[jetty-util-9.4.0.v20161208.jar.8141124450067202531.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.Server.doStart(Server.java:431) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
... 10 common frames omitted
Caused by: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method) ~[na:1.8.0_242]
at sun.nio.ch.Net.bind(Net.java:433) ~[na:1.8.0_242]
at sun.nio.ch.Net.bind(Net.java:425) ~[na:1.8.0_242]
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:220) ~[na:1.8.0_242]
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:85) ~[na:1.8.0_242]
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:298) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) ~[jetty-util-9.4.0.v20161208.jar.8141124450067202531.tmp:9.4.0.v20161208]
at org.eclipse.jetty.server.Server.doStart(Server.java:431) ~[jetty-server-9.4.0.v20161208.jar.6831686875779823992.tmp:9.4.0.v20161208]
... 10 common frames omitted

Subsequent restarts give me the "database already in use" errors.

That launched Ubooquity, but now when I try to access via web gui I get 500 errors again:

i don't know how to format for codeblocks in this forum, i tried using the html <code> </code> tags, but that didn't work. please ignore those if you see them above and think they are causing issues.