Crawlers slowly killing management UI accessibility

I’m testing with JDK 11 now. The reason for this it does have more advanced GCs then JDK 8. Anyway JDK 11 is much more strict in honoring mx/ms setup hence I needed to low from 59g to 39g which is kind of managable in 64g VM.

Now, when yacy is started it process whole crawlers queue – probably load it into the RAM and on JDK 11 I see following exception:

I 2021/08/06 21:15:54 HostQueue opened HostQueue /yacy/data/stable/yacy/DATA/INDEX/freeworld/QUEUES/CrawlerCoreStacks/www.sprachenzentrum.uni-trier.de-#8wNMhB.80 with 1 urls.
W 2021/08/06 21:15:54 ConcurrentLog java.lang.NullPointerException
java.lang.NullPointerException
	at java.base/java.util.TreeMap.rotateLeft(TreeMap.java:2221)
	at java.base/java.util.TreeMap.fixAfterInsertion(TreeMap.java:2268)
	at java.base/java.util.TreeMap.put(TreeMap.java:580)
	at net.yacy.kelondro.table.Table.<init>(Table.java:273)
	at net.yacy.kelondro.index.OnDemandOpenFileIndex.getIndex(OnDemandOpenFileIndex.java:61)
	at net.yacy.kelondro.index.OnDemandOpenFileIndex.has(OnDemandOpenFileIndex.java:190)
	at net.yacy.kelondro.index.BufferedObjectIndex.has(BufferedObjectIndex.java:179)
	at net.yacy.crawler.HostQueue.has(HostQueue.java:397)
	at net.yacy.crawler.HostBalancer.has(HostBalancer.java:244)
	at net.yacy.crawler.HostBalancer.push(HostBalancer.java:284)
	at net.yacy.crawler.data.NoticedURL.push(NoticedURL.java:193)
	at net.yacy.crawler.CrawlStacker.stackCrawl(CrawlStacker.java:401)
	at net.yacy.crawler.CrawlStacker.process(CrawlStacker.java:140)
	at net.yacy.crawler.CrawlStacker.process(CrawlStacker.java:65)
	at net.yacy.kelondro.workflow.InstantBlockingThread.job(InstantBlockingThread.java:72)
	at net.yacy.kelondro.workflow.AbstractBlockingThread.run(AbstractBlockingThread.java:82)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)
I 2021/08/06 21:15:54 HostQueue opened HostQueue /yacy/data/stable/yacy/DATA/INDEX/freeworld/QUEUES/CrawlerCoreStacks/motel-6-savannah-richmond-hill.booked.net-#3ll-5w.443 with 1 urls.
I 2021/08/06 21:15:54 LOADER CRAWLER Redirection detected ('HTTP/1.1 301 Moved Permanently') for URL http://codegolf.meta.stackexchange.com/robots.txt
I 2021/08/06 21:15:54 LOADER CRAWLER ..Redirecting request to: https://codegolf.meta.stackexchange.com/robots.txt
I 2021/08/06 21:15:54 LOADER CRAWLER Redirection detected ('HTTP/1.1 301 Moved Permanently') for URL http://codegolf.stackexchange.com/robots.txt
I 2021/08/06 21:15:54 LOADER CRAWLER ..Redirecting request to: https://codegolf.stackexchange.com/robots.txt
I 2021/08/06 21:15:55 org.apache.solr.update.DirectUpdateHandler2 start commit{,optimize=false,openSearcher=true,waitSearcher=true,expungeDeletes=false,softCommit=true,prepareCommit=false}
I 2021/08/06 21:15:55 REJECTED https://ghc.haskell.org/robots.txt - no response body (http return code = 404)
I 2021/08/06 21:15:55 org.apache.solr.update.DirectUpdateHandler2 end_commit_flush
I 2021/08/06 21:15:55 org.apache.solr.core.QuerySenderListener QuerySenderListener sending requests to Searcher@1fee20a2[collection1] main

and it looks like my UI is dead again.