Unable to connect to apache solr - process restart needed - performance

I am facing a strange problem with solr. After running solr for few hours, client starts reporting error message that it is unable to contact the solr, although solr instance is up on the server.
I can't see any high traffic on website which sometimes is the reason of connection refusal.
This issue gets fixed after solr restart.
Any idea what is going wrong here ?

Answer to most of the problems can be found in logs. Thanks D_K for reminding me.
SEVERE: java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space
I have increased the heap size to fix this issue.
java -Xms<initial heap size> -Xmx<maximum heap size>
Also, we have reduced document size by removing unnecessary information which we don't need to retain in solr.

If you have a client with long running connection but low amount of traffic, you may have a firewall in between. Firewalls have limited-size routing tables, so they eventually drop the mapping for connections they haven't seen for a while.
Try sending a ping query every 30 minutes or so through that specific connection and see if the issue goes away. If you need to validate it, run Wireshark on the client and see whether the client is getting RST (reset) packets from an unexpected end point (that would be firewall).

You just need to add your collection in solr by following the step given in this url ( https://drupal.stackexchange.com/questions/95897/apache-solr-4-6-0-insta... ) and then select your collection from your solr which is running on localhost or live site (http://localhost:8983/solr/) and go to schema tab. Click schema tab and then you can see you schema file attach in apachesolr module.
You now just need to your schema url which just look like this http://localhost:8983/solr/your_core_name/. Now add this url in apachesolr module.
Then it will show that your site has contacted apache solr server in your drupal site.

Related

Oracle ORDS: Get request returns old data, then after period of time the changed data

I am having a problem with the Oracle Rest Data Services (short ORDS) and I can't find a solution.
The Problem is as follows:
We are using ORDS via a TomCat Webserver and I have 2 Endpoints defined, one to Update a dataset and one to get all datasets from this table.
If I update the value via my Endpoint the change is written in the Table, but if I try to get the table with this change ORDS only response with the old not changed table. After a certain period of Time while constantly trying to get the change it repondes with the expected values. (happens after max 1 minute, can be earlier).
Because of this behaviour I accused some type of caching, but I cant find no configuration in the oracle database or on the TomCat.
Another Point for this theory was that I logged what happens in my GET procedure and found that only the one request with the correct values gets logged, like the others didnt even happen ..
The Request giving me the old value are coming back in the 4-8 ms range while the request with the correct data is in the 100-200 ms.
Ty for your help :)
I tried logging what happens, but I got that only the request with the fresh values was logged.
I tried to restart the TomCat Webserver to make sure that the cache is cleared, but this didnt fix the Problem
I searched for a configuration in ORDS or oracle where a cache would be defined, but it was never set.
I tried to set the value via a SQL update and not an endpoint, but even here I get the change only delayed
Do you have a full overview of the communication path? Maybe there is a proxy between?
When the TomCat has no caching configuration and you restartet the webserver during your tests and still have the same issue, then there is maybe more...
Kind regards
M-Achilles

Periodic tns-12531: TNS: Cannot allocate memory

I have a problem that's been plaguing me about a year now. I have Oracle 12.1.x.x installed on my machine. After a day or two the listener stops responding and the listener.log contains a bunch of TNS-12531 messages. If I reboot, the problem goes away and I'm fine for another day or two. I'm lazy and I hate rebooting, so I decided to finally track this down, but I'm having no luck. Since the alternative is to do work that I really don't want to do, I'm going to spend all my time researching this.
Some notes:
Windows 10 Pro
64-Bit
32 GB RAM
Generally, about 20GB free when the error occurs
I have several databases and it doesn't matter which DB is running
Restarting the DB doesn't help
Restarting the listener doesn't help
Only rebooting clears the problem
When I set TRACE_LEVEL_LISTENER = 16, I don't get much more info. Trace files are not written to
I can connect to the DB if I bypass the listener (ie, set ORACLE_SID=xxx and connect without a DB identifier)
All other network interactions seem to work fine after the listener stops
lsnrctl status hangs and adds another TNS-12531 to the listener.log
I have roughly the same config at home and this does not happen
Below is an example of a listener.log file:
Fri Jul 28 14:21:47 2017
System parameter file is D:\app\user\product\12.1.0\dbhome_1\network\admin\listener.ora
Log messages written to D:\app\user\diag\tnslsnr\LJ-Quad\listener\alert\log.xml
Trace information written to D:\app\user\diag\tnslsnr\LJ-Quad\listener\trace\ora_24288_14976.trc
Trace level is currently 16
Started with pid=24288
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=LJ-Quad)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
Listener completed notification to CRS on start
TIMESTAMP * CONNECT DATA [* PROTOCOL INFO] * EVENT [* SID] * RETURN CODE
28-JUL-2017 14:22:06 * 12531
TNS-12531: TNS:cannot allocate memory
28-JUL-2017 14:22:47 * 12531
TNS-12531: TNS:cannot allocate memory
28-JUL-2017 14:26:24 * 12531
TNS-12531: TNS:cannot allocate memory
Thanks a bunch for any help you can provide!
Issue 1
This error can occur approximately after 2048 connections have been made via the listener when running on a non-English Windows installation.
Fix for Issue 1
Create a Windows User Group named Administrators on the computer where the listener.exe resides. This can fix the issue of the listener dying.
Reference: I'll post the link for the first issue as soon as I find it again
Issue 2
This error can also occur on Windows 64-Bit systems where the Desktop Application Heap is too small.
Fix for Issue 2
Try to Increase the Desktop Application Heap Registry in windows its located in
HKLM\System\CurrentControlSet\Control\Session Manager\SubSystems\Windows
Just as note don't add this Value by yourself, you have to depend on document.
Basically search for the registry entry and alter the third value for the key SharedSection=1024,20480,1024. This is a trial and error approach, but seems to improve listener's stability and memory issues.
Reference: TNS:cannot allocate memory - is there limit to the num databases on one box (Oracle Developer Community)

What does the error "Bad gateway" mean on Kibana Dashboard?

I have a "Elastic-search + Kibana" instance which has a lot of data. I have another HAProxy instance which redirects connection to Kibana dashboard.
I am having a issue where the Kibana Dashboard isn't able to search (*) , it takes too much time & eventually throws this -:
I want to know why is this happening or what exactly "Bad Gateway" mean. Moreover what to can be done to solve this.
Found the solution , it was the issue of Elastic_search tuning. I had to allocate half of the memory to ES_HEAP_SIZE & did some tweaks on elasticsearch.yml which doesn't allow JVM to swap memory.
I got the same problem, I restarted my browser, then it back to normal again.

The slowness about Websphere Application Server's app Admin Console

It's the concern about Admin console's performance from Websphere Application Server.
I can login smoothly without any problem, but it's got be very slow on response when doing operations such as showing Node status by clicking "Nodes" under "System administration", showing AppServer status by clicking "Application Servers" under "Servers" etc. However, the funny thing is the problem is more serious on remote node than the local nodes which locate on same box with DmgrNode.
So i suspect it should be the problem with network communication between DmgrNode and remote Node, but i don't know how to fix it.
Anybody got the same issue here??? Or any idea to figure it out? Please do me a favor, please please .......
When the console gets the list of servers to display, it does make mbean calls to all of the servers, and if there is a network problem between the dmgr and the node, this could cause some delay in displaying the server page. The nodes page, however, should not have that issue. What is your topology? How many nodes/servers and how many are local/remote?
How can you tell the problem is more serious on the remote nodes than the local nodes?
Are other console operations slower, or only ones that display status? Do you have the same problem with wsadmin commands? The console issues a queryNames to search for the server mbeans. Does the following wsadmin command run much more slowly on the remote node than the local node? If so, how much more slowly?
print AdminControl.queryNames('WebSphere:type=Server,node=myNode')
Replace myNode with either the local or remote node name.
I assume you are using IE to fire up the console. Fire the console from Chrome and see if it helps.

JDBC URL for Oracle XA client

Using the JDBC driver oracle.jdbc.xa.client.OracleXADataSource, what is the correct format of the JDBC URL? The thin format of
jdbc:oracle:thin:#host:port:sid
does not work. WebSphere is reporting that the given url (which is otherwise correct) is invalid.
The test connection operation failed for data source Oracle MyDB (XA) on
server nodeagent at node MY_node with the following exception:
java.sql.SQLException: Invalid Oracle URL specifiedDSRA0010E: SQL State = 99999,
Error Code = 17,067. View JVM logs for further details.
There is nothing in the JVM logs.
Whether you use a XA Driver or not, the JDBC connection string is the same (and the format of your question is correct).
For me the issue resolved by adding alias name, username and password in JAAS - J2C authentication data. And also selecting this entry as Component-managed authentication alias.
In case this happens to anyone else. The problem went away after restarting websphere.
In my case, the problem went away when I change the authentication property of the jdbc resource reference from Authentication=Application to Authentication=Container
Had the same issue. Dont know about simple deployments, but on a two nodes cluster, I restarted the first node, and the connection started working on it (not on the second). Restarted the second node, and the connection started working there too.
So just restart the nodes (I also restarted the nodeAgents, but i don't know if it's necessary).
if you are doing using wsadmin command then you need to stop manager,stop node,start manager, sync node and then start node (I mean full sync). Hopefully this will resolve the issue. I dont know why but this resolves my issue.

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