Say I want to monitor number of concurrent user at this moment in our production server using Zabbix http://www.zabbix.com/. Can anyone let me know how can I do that? The servers are written in java.
First question to answer is: how you can query the number of users on the server? Is this something you can grep out of some log file? Or maybe your 'server written in java' allows to query the user count in some standardized way (i.e. via http)?
You might be able to use one of standard zabbix checks, but most probably you'll have to configure zabbix agent running at your server to monitor a custom User Parameter: https://www.zabbix.com/documentation/1.8/manual/config/user_parameters.
So, needed value should be parsed out of json available via http. Starting with version 2.2 you'll be able to do it with web.page.regexp[] but since it's not production ready yet you'll have to stick to custom user items.
Supposedly zabbix agent is running on linux. Open the zabbix_agentd.conf and add the following line:
UserParameter=json.query[*], value=$(curl -s $1 | grep -Eo "\"$2\":(\w*)"| cut -d: -f2); if [ -z "$value" ]; then echo "not found"; else echo $value; fi
Restart the agent. After this new user parameter json.query will become available as "Zabbix Agent" type item on this server. It takes two arguments: address of json to fetch and name of variable to extract. I was testing on the following sample:
"usercount":30
You might need to alter the regex if your json is formatted differently.
Now you need to add the new zabbix item: Configuration/Hosts/Items - Create Item
Description: Concurrent user count
Type: Zabbix Agent
Key: json.query[myserver.com/status.json,usercount]
Data Type: numeric
That's it. User count is now monitored and you can reference it in zabbix triggers the usual way.
Related
So apologies if what I ask is trivial but I am experimenting with Memcached and Jmeter. I have a Memcached server setup (as far as I can tell) and am able to make telnet requests to it via telnet IP PORT and additionally set and get using commands set and get appropriately.
Now point me to a different application if perhaps this is the wrong choice; but my understanding was that Jmeter should allow me to pound the server with equivalent Set and Get requests.
Unfortunately the experimental platform is a remote linux PC running Rockylinux which is similar to CentOS / RedHat to my understanding (I didn't set this part up); and as a result I do not have a GUI to launch while on the Linux PC. I have however opened Jmeter up on my local PC on windows and understand I should be able to send the test file over and run it.
I followed these instructions to try to setup a TCP sampler and set the "text to send" field as below; after doing the additional step in the link regarding the precompiler.
set tutorialspoint 0 900 9${CR}${LF}
memcached${CR}${LF}
quit${CR}${LF}
Running the above as a headless jmeter session doesn't generate any errors called [./jmeter -n -t "Sample.jmx" -l testresults.jtl"] but when I connect via telnet I'm also not seeing the value for the key "tutorialspoint" get updated. When manually doing the get and set I am seeing updates. Any ideas what I could be doing wrong? Checking the log indicates ResponseCode 200 OK as expected. Is there a good method to debug something in a Headless setup?
Thanks for your time.
I believe the easiest way is using Memcached Java Client library
Download spymemcached-2.12.3.jar and drop it to "lib" folder of your JMeter installation (or any other location in JMeter Classpath)
Restart JMeter to pick the .jar up
Add JSR223 Sampler to your test plan and use the following code snippets:
def client = new net.spy.memcached.MemcachedClient(new InetSocketAddress('your-memcached-host', your-memcached-port)) - for connecting to the server
client.set('tutorialspoint', 900, 'memcached').done to write memcached to the tutorialspoint key for 15 minutes
client.get('tutorialspoint') - to read the value of tutorialspoint key
client.shutdown() - to disconnect
More information on Groovy scripting in JMeter: Apache Groovy - Why and How You Should Use It
Demo:
I used command "docker run -p 8080/8080 --name my_local_image ...." and it failed saying Unable to find image '8080/8080:latest' locally
8080/8080 = what this two port represents exactly ?
Replace this " -p 8080/8080 " by this " -p 8080:8080 "
The first port : the Docker host ( you can use this port to access to your container) to access to the container from the outside.
the second one : is the port used by your application.
Example : I want to run tomcat server in a docker container, the default port of tomcat is 8080 and I want to expose my docker on port 9000 so i have to write :
docker run -p 9000:8080 --name myTomcatContainer tomcat
So with this configuration I can access to Tomcat from outside using :
http://host-ip:9000
The -p option is used to expose the ports that are used for the image instance. The first one is the hostport and the second parameter after the ":" fullcolon is the container port to which it should be mapped . For more details read doc.
The error that you received while launching the instance using docker run tells us that the image name that you provided with the command is not locally available on the machine that you are using, it might also be an issue with the way that you provided the ports using '/' instead of ":" .So , to be safe, use docker pull first to pull the latest image from repo and then run it with proper syntax.
--expose=[]: Expose a port or a range of ports inside the container.
These are additional to those exposed by the EXPOSE instruction
-P : Publish all exposed ports to the host interfaces
-p=[] : Publish a container's port or a range of ports to the host
format: ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort
Both hostPort and containerPort can be specified as a
range of ports. When specifying ranges for both, the
number of container ports in the range must match the
number of host ports in the range, for example:
-p 1234-1236:1234-1236/tcp
When specifying a range for hostPort only, the
containerPort must not be a range. In this case the
container port is published somewhere within the
specified hostPort range. (e.g., -p 1234-1236:1234/tcp)
(use 'docker port' to see the actual mapping)
--link="" : Add link to another container (:alias or )
Just to add a little to the already good answers here, I like to use the analogy of finding a friends apartment in a city to explain port numbers.
In this analogy, the
Host OS == neighborhood where the apartment complex is
Your application == the apartment complex
Exposed port within the application == the specific apartment in the complex
If you're trying to find someone's address, you'll find the neighborhood of the user (in this case it would be the URL, most likely http://localhost if developing locally)
But then you need the street number of the apartment complex, that number is the first number in something like 5000:8080, so your application is exposed on the host OS at port 5000, the friends street address is 5000, localHost street.
But once you get to the apartment complex, you still need to know which door to knock on. You've arrived at the apartment complex (your application), but where does your friend live specifically? That's the second number, the 5000:8080.
So your friend's network address is the combination of the URL, port within the host OS (if you're developing locally, this is your computer, if not, it's whatever server the app is running on) and port exposed within the application.
Note that an apartment complex usually has more than one apartment, but it's still at the same address, so it's very possible that your application exposes more than one port, something like 5000:8081, or 5000:9000.
It's also possible that two apartments in different buildings will have the same apartment number, so we can have 5000:8080, as well as 8080:8080, neither this nor the previous situation will cause a conflict in network traffic.
This image is an example of the last case I mentioned
Could you please assist me with the following issue.
I use Apiman version 1.2.1
FROM jboss/wildfly:9.0.2.Final
ENV APIMAN_VERSION 1.2.1.Final
I expose this version via kubernetes, as a persistent volume I use postgres in the same container. Once I create it at the first time, after this in the apiman I have added Organization/ API/.... and all necessary staff.
I press on button to publish api, and may check that it works perfect, so I use kubectl port-forward pod-name 8080:8080 and may check my gateway via browser http:localhost:8080/apiman-gateway/ORgId/bla/bla/bla/bla?givemedescriptionbyid=1.
After this one I go to console and kill apiman pod, as a result of pod restart, the same operation kubectl port-forward new-pod-name 8080:8080, and I can see that the all data of apiman like organization, apis and all other staff is already there.
But one big problem if you try to call gateway again, it tells you that:
{"responseCode":500,"message":"API not
found.","trace":"io.apiman.gateway.engine.beans.exceptions.InvalidApiException:
API not found.\n\tat
io.apiman.gateway.engine.impl.ApiRequestExecutorImpl$3.handle(ApiRequestExecutorImpl.java:278)\n\tat
io.apiman.gateway.engine.impl.ApiRequestExecutorImpl$3.handle(ApiRequestExecutorImpl.java:271)\n\tat
io.apiman.gateway.engine.impl.SecureRegistryWrapper$1.handle(SecureRegistryWrapper.java:122)\n\tat
io.apiman.gateway.engine.impl.SecureRegistryWrapper$1.handle(SecureRegistryWrapper.java:111)\n\tat
io.apiman.gateway.engine.es.CachingESRegistry.getApi(CachingESRegistry.java:116)\n\tat
io.apiman.gateway.engine.impl.SecureRegistryWrapper.getApi(SecureRegistryWrapper.java:111)\n\tat
io.apiman.gateway.engine.impl.ApiRequestExecutorImpl.execute(ApiRequestExecutorImpl.java:270)\n\tat
io.apiman.gateway.platforms.servlet.GatewayServlet.doAction(GatewayServlet.java:232)\n\tat
io.apiman.gateway.platforms.servlet.GatewayServlet.doGet(GatewayServlet.java:77)\n\tat
javax.servlet.http.HttpServlet.service(HttpServlet.java:687)\n\tat
javax.servlet.http.HttpServlet.service(HttpServlet.java:790)\n\tat
io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:86)\n\tat
io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)\n\tat
io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)\n\tat
org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)\n\tat
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)\n\tat
io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)\n\tat
io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)\n\tat
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)\n\tat
io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)\n\tat
io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)\n\tat
io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58)\n\tat
io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:72)\n\tat
io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)\n\tat
io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76)\n\tat
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)\n\tat
org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)\n\tat
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)\n\tat
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)\n\tat
io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:282)\n\tat
io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:261)\n\tat
io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:80)\n\tat
io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:172)\n\tat
io.undertow.server.Connectors.executeRootHandler(Connectors.java:199)\n\tat
io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:774)\n\tat
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)\n\tat
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)\n\tat
java.lang.Thread.run(Thread.java:745)\n"}
I can see, that by metrics of calls in api manager, all my calls can reach apiman-gateway, but I get 500 response code.
If anybody will met such error, so, I have solved it with the following steps, first of all we need to use only new version of APIMAN, list of fixes already implemented. And also apiman-gateway cannot live without elastic search to restore itself. Hence elasticsearch configuration should to be provided.
I've installed the latest RabbitMQ server (rabbitmq-server-3.3.0-1.noarch.rpm) on a fresh Centos 5.10 VM according to the instructions on the official site.
I've done this many times before during development and never had any issues. However, this time I cannot log into the management web interface using the default guest/guest user.
In the logs, I see the following:
=ERROR REPORT==== 4-Apr-2014::00:55:15 ===
webmachine error: path="api/whoami"
"Unauthorized"
What could be causing this?
It's new features since the version 3.3.0
http://www.rabbitmq.com/release-notes/README-3.3.0.txt
server
------
...
25603 prevent access using the default guest/guest credentials except via
localhost.
If you want enable the guest user read this or this RabbitMQ 3.3.1 can not login with guest/guest
# remove guest from loopback_users in rabbitmq.config like this
[{rabbit, [{loopback_users, []}]}].
# It is danger for default user and default password for remote access
# better to change password
rabbitmqctl change_password guest NEWPASSWORD
If you want create a new user with admin grants:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Now you can access using test test.
If you still can't access the management console after a fresh install, check if the management console was enabled. To enable it:
Go to the RabbitMQ command prompt.
Type:
rabbitmq-plugins enable rabbitmq_management
Something that just happened to me and caused me some headaches:
I have set up a new Linux RabbitMQ server and used a shell script to set up my own custom users (not guest!).
The script had several of those "code" blocks:
rabbitmqctl add_user test test
rabbitmqctl set_user_tags test administrator
rabbitmqctl set_permissions -p / test ".*" ".*" ".*"
Very similar to the one in Gabriele's answer, so I take his code and don't need to redact passwords.
Still I was not able to log in in the management console. Then I noticed that I had created the setup script in Windows (CR+LF line ending) and converted the file to Linux (LF only), then reran the setup script on my Linux server.
... and was still not able to log in, because it took another 15 minutes until I realized that calling add_user over and over again would not fix the broken passwords (which probably ended with a CR character). I had to call change_password for every user to fix my earlier mistake:
rabbitmqctl change_password test test
(Another solution would have been to delete all users and then call the script again)
If on Windows and installed using chocolatey make sure firewall is allowing the default ports for it:
netsh advfirewall firewall add rule name="RabbitMQ Management" dir=in action=allow protocol=TCP localport=15672
netsh advfirewall firewall add rule name="RabbitMQ" dir=in action=allow protocol=TCP localport=5672
for the remote access.
I also couldn't log in to Rabbit's web interface. in my case, cookies were disabled in the browser for this web interface. I allowed cookies to be saved and rebooted chrome. and I was able to log in again.
If you are in Mac OS, you need to open the /usr/local/etc/rabbitmq/rabbitmq-env.conf and
set NODE_IP_ADDRESS=, it used to be 127.0.0.1. Then add another user as the accepted answer suggested.
After that, restart rabbitMQ, brew services restart rabbitmq
I have a Tomcat installation where I suspect the thread pool may be decreasing over time due to threads not being properly released. I get an error in catalina.out when maxthreads is reached, but I would like to log the number of threads in use to a file every five minutes so I can verify this hypothesis. Would anyone please be able to advise how this can be be done?
Also in this installation there is no Tomcat manager, it appears whoever did the original installation deleted the manager webapp for some reason. I'm not sure if manager would be able to do the above or if I can reinstall it without damaging the existing installation? All I really want to do is keep track of the thread pool.
Also, I noticed that maxthreads for Tomcat is 200, but the max number of concurrent connections for Apache is lower (Apache is using mod_proxy and mod_proxy_ajp (AJP 1.3) to feed Tomcat). That seems wrong too, what is the correct relationship between these numbers?
Any help much appreciated :D
Update: Just a quick update to say the direct JMX access worked. However I also had to set Dcom.sun.management.jmxremote.host. I set it to localhost and it worked, however without it no dice. If anyone else has a similar problem trying to enable JMX I recommend you set this value also, even if you are connecting from the local machine. Seems it is required with some versions of Tomcat.
Just a quick update to say the direct JMX access worked. However I also had to set Dcom.sun.management.jmxremote.host. I set it to localhost and it worked, however without it no dice. If anyone else has a similar problem trying to enable JMX I recommend you set this value also, even if you are connecting from the local machine. Seems it is required with some versions of Tomcat.
Direct JMX access
Try adding this to catalina.sh/bat:
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=5005
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
UPDATE: Alex P suggest that the following settings might also be required in some situations:
-Dcom.sun.management.jmxremote.host=localhost
This enables remote anonymous JMX connections on port 5005. You may also consider JVisualVM which is much more please and allows to browse JMX via plugin.
What you are looking for is Catalina -> ThreadPool -> http-bio-8080 -> various interesting metrics.
JMX proxy servlet
Easier method might be to use Tomcat's JMX proxy servlet under: http://localhost:8080/manager/jmxproxy. For instance try this query:
$ curl --user tomcat:tomcat http://localhost:8080/manager/jmxproxy?qry=Catalina:name=%22http-bio-8080%22,type=ThreadPool
A little bit of grepping and scripting and you can easily and remotely monitor your application. Note that tomcat:tomcat is the username/password of user having manager-jmx role in conf/tomcat-users.xml.
You can deploy jolokia.war and then retrieve mbeans values in JSON (without the manager):
http://localhost:8080/jolokia/read/Catalina:name=*,type=ThreadPool?ignoreErrors=true
If you want only some values (currentThreadsBusy, maxThreads, currentThreadCount, connectionCount):
http://localhost:8080/jolokia/read/Catalina:name=*,type=ThreadPool/currentThreadsBusy,maxThreads,currentThreadCount,connectionCount?ignoreErrors=true
{
request: {
mbean: "Catalina:name="http-nio-8080",type=ThreadPool",
attribute: [
"currentThreadsBusy",
"maxThreads",
"currentThreadCount",
"connectionCount"
],
type: "read"
},
value: {
currentThreadsBusy: 1,
connectionCount: 4,
currentThreadCount: 10,
maxThreads: 200
},
timestamp: 1490396960,
status: 200
}
Note: This example works on Tomcat7 +.
For a more enterprise solution. I have been using New Relic in our production environment.
This provides a graph of the changes to the threadpool over time.
There are cheaper tools out meanwhile: I am using this jar here: https://docs.cyclopsgroup.org/jmxterm
You can automate it via shell/batch scripts. I regexed the output and let prometheus poll it for displaying it in grafana.