I recently upgrade our Neo4j Enterprise to v3.5.9. The problem is that since the DB started, any write query hangs for 60seconds and the query is killed by the runtime (We have dbms.transaction.timeout=60s in the config)
Even this simple query will never complete:
create (:Foo)
Or one with a SET statament:
match(n:Node)
where n.uuid = $uuid
set n.updateDate = "2019-09-04T22:27:31.516Z"
On the other hand, read queries are fine. Only writes are hanging.
I see a lot of lines like this on my debug.log:
I think that Graphaware uuid plugin it's involve in this. I removed the plugin and its configs, then restarted the database and it works as usual. The problem is that we really depend on this plugin.
I am not sure if this is related but when I run sudo service neo4j stop it timeout. I have to sudo kill -9 <pid> to stop the database 
call dbms.listTransactions() and call dbms.listActiveLocks() did not provide useful information .
call dbms.listTransactions(), shows three rows, one for the procedure and two almost empty rows. There is no queryId which I need in order to call dbms.listActiveLocks().
I studied the APOC support, I wish we could have a way to install handlers for all nodes and relationships at once. I understood we'd need to call apoc.uuid.install() for each label.
So, after startup I see two very long running transactions. They seem to be internal transactions because they do not have query-id. They have high values for page hits and page faults, the last I checked had 5810 page hits and 209 page faults.
I debugged the code for graphaware server and uuid and found that when the uuid module bootstraps it's calling all the nodes in the graph through a series of wrappers that finally invoke getAllNodes method in GraphDatabaseService class. This is where the process hangs. The result getAllNodes is expected to execute a unit of work nothing is generated.
Now I increases the timeout for transactions, it used to be 1minute and now it's 1hour. I am crossing fingers to see it load successfully. 
Here is where the uuid module initializes
Here it waits for the result of getAllNodes. My logs point to the line 86 on this file.
Upgraded from 3.1.1, we have about 9 million nodes, they all had uuid assigned before and we are using enterprise edition.
I think it was an issue with the database store. We mounted a backup of our production store on the dev instance then we did the upgrade and all went good. Also the previous store use to take long times to startup.
Fortunately, we solved our problem 
.
@Luanne_Misquitta, I am experiencing the same problem again on our dev DB , I am pretty sure it has something to do with the initialization of Graphaware uuid module. If I disable this module startup is fast and I can do write queries almost immediately.
When Uuid module is enable, Neo4j starts but I can't do any write queries. The last time I let it run for about 10 hours and I still couldn't.
I have a server with 30GB of ram, I have tested different heap and page cache configurations such as: 18GB for heap, 8 for page cache and the other way around 8GB for heap and 18 for page cache. My store in the version is about 13GB.
Each time I see the module initializing:
2019-09-11 16:19:51.064+0000 INFO Module UIDM seems to have been registered for the first time.
2019-09-11 16:19:51.064+0000 INFO Module UIDM seems to have been registered for the first time, will try to initialize...
And a lot of GC pauses on the debug.log
2019-09-11 16:33:11.966+0000 WARN [o.n.k.i.c.VmPauseMonitorComponent] Detected VM stop-the-world pause: {pauseTime=109, gcTime=115, gcCount=1}
2019-09-11 16:34:57.481+0000 WARN [o.n.k.i.c.VmPauseMonitorComponent] Detected VM stop-the-world pause: {pauseTime=104, gcTime=121, gcCount=1}
2019-09-11 16:35:31.614+0000 WARN [o.n.k.i.c.VmPauseMonitorComponent] Detected VM stop-the-world pause: {pauseTime=108, gcTime=117, gcCount=1}
2019-09-11 16:36:10.861+0000 WARN [o.n.k.i.c.VmPauseMonitorComponent] Detected VM stop-the-world pause: {pauseTime=115, gcTime=116, gcCount=1}
It'd be great if you can help me figure out what's going on.
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