Add notes for 2020-12

content/posts/2020-12.md

@@ -21,4 +21,61 @@ $ chrt -b 0 dspace dsrun com.atmire.statistics.util.update.atomic.AtomicStatisti
 - AReS went down when the `renew-letsencrypt` service stopped the `angular_nginx` container in the pre-update hook and failed to bring it back up
   - I ran all system updates on the host and rebooted it and AReS came back up OK
 
+## 2020-12-02
+
+- Udana emailed me yesterday to ask why the CGSpace usage statistics were showing "No Data"
+  - I noticed a message in the Solr Admin UI that one of the statistics cores failed to load, but it is up and I can query it...
+  - Nevertheless, I restarted Tomcat a few times to see if all cores would come up without an error message, but had no success (despite that all cores ARE up and I can query them, _sigh_)
+  - I think I will move all the Solr yearly statistics back into the main statistics core
+- Start testing export/import of yearly Solr statistics data into the main statistics core on DSpace Test, for example:
+
+```
+$ ./run.sh -s http://localhost:8081/solr/statistics-2010 -a export -o statistics-2010.json -k uid
+$ ./run.sh -s http://localhost:8081/solr/statistics -a import -o statistics-2010.json -k uid
+$ curl -s "http://localhost:8081/solr/statistics-2010/update?softCommit=true" -H "Content-Type: text/xml" --data-binary "<delete><query>*:*</query></delete>"
+```
+
+- I deployed Tomcat 7.0.107 on DSpace Test (CGSpace is still Tomcat 7.0.104)
+- I finished migrating all the statistics from the yearly shards back to the main core
+
+## 2020-12-05
+
+- I deleted all the yearly statistics shards and restarted Tomcat on DSpace Test (linode26)
+
+## 2020-12-06
+
+- Looking into the statistics on DSpace Test after I migrated them back to the main core
+  - All stats are working as expected... indexing time for the DSpace Statistics API is the same... and I don't even see a difference in the JVM or memory stats in Munin other than a minor jump last week when I was processing them
+- I will migrate them on CGSpace too I think
+  - First I will start with the statistics-2010 and statistics-2015 cores because they were the ones that were failing to load recently (despite actually being available in Solr WTF)
+
+![Error message in Solr admin UI about the statistics-2010 core failing to load](/cgspace-notes/2020/12/solr-statistics-2010-failed.png)
+
+- First the 2010 core:
+
+```console
+$ chrt -b 0 ./run.sh -s http://localhost:8081/solr/statistics-2010 -a export -o statistics-2010.json -k uid
+$ chrt -b 0 ./run.sh -s http://localhost:8081/solr/statistics -a import -o statistics-2010.json -k uid
+$ curl -s "http://localhost:8081/solr/statistics-2010/update?softCommit=true" -H "Content-Type: text/xml" --data-binary "<delete><query>*:*</query></delete>"
+```
+
+- Judging by the DSpace logs all these cores had a problem starting up in the last month:
+
+```console
+# grep -rsI "Unable to create core" [dspace]/log/dspace.log.2020-* | grep -o -E "statistics-[0-9]+" | sort | uniq -c
+     24 statistics-2010
+     24 statistics-2015
+     18 statistics-2016
+      6 statistics-2018
+```
+
+- The message is always this:
+
+```
+org.apache.solr.client.solrj.impl.HttpSolrServer$RemoteSolrException: Error CREATEing SolrCore 'statistics-2016': Unable to create core [statistics-2016] Caused by: Lock obtain timed out: NativeFSLock@/[dspace]/solr/statistics-2016/data/index/write.lock
+```
+
+- I will migrate all these cores and see if it makes a difference, then probably end up migrating all of them
+  - I removed the statistics-2010, statistics-2015, statistics-2016, and statistics-2018 cores and restarted Tomcat and _all the statistics cores came up OK and the CUA statistics are OK_!
+
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