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- Details
1. Add Jackson maven dependency to your project
<dependencies>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.8.5</version>
</dependency>
</dependencies>
2. Use ObjectMapper class
ObjectMapper mapper = new ObjectMapper();
//to array
MyClass[] myObjects = mapper.readValue(myJson, MyClass[].class);
//to list 1
List<MyClass> myObjects = mapper.readValue(jsonInput, new TypeReference<List<MyClass>>(){});
//to list 2
List<MyClass> myObjects = mapper.readValue(jsonInput, mapper.getTypeFactory().constructCollectionType(List.class, MyClass.class));
- Details
If your Java application uses Spring Data for accessing to MongoDB and it throws error messages like this: "... Not authorized for query ..." or this: "... errmsg" : "unauthorized... ",
then check your application context xml-file:
<mongo:db-factory dbname="${mongo.database}" host="${mongo.host}" id="mongoDbFactory" port="${mongo.port}" username="${mongo.username}" password="${mongo.password}"/>
I used Spring Roo for source code generating and attributes username and password weren`t generated per default.
- Details
After adding of the MongoDB cartridge to your application you can not build a connection from your local client (MongoVue or Unit tests from your Application) because usings ports are closed.
Follow steps will help you:
1. Activate a port forwarding to your application:
rhc port-forward -a <your_application_name>
you will get a message like this:
Service Local OpenShift
------- --------------- ---- --------------------------------------------------------
haproxy 127.0.0.1:8080 => 127.3.6.2:8080
...
mongodb 127.0.0.1:55131 => <your_app_domain>.rhcloud.com:55131
2. keep the executing of the port forwarding and use local IP and Port (127.0.0.1:55131) of MongoDB for building your connection
- Details
During the Tomcat starting:
The BASEDIR environment variable is not defined correctly. This environment variable is needed to run this program
To Do:
enable current user to execute the startup files
cd {tomcat-home}/bin
chmod +x *.sh
Error:
Unable to set localhost. This prevents creation of a GUID. Cause was: myhost : myhost java.net.UnknownHostException: myhost : myhost
To Do:
in /etc/hosts eintragen:
127.0.0.1 myhost localhost
- Details
Sysstat ist eine Sammlung von System-Überwachungswerkzeugen für Linux (CPU, RAM, Swapping, I/O, Netzwerk usw.). Sysstat ist Open Source.
Man definiert Zeitabstände, wie oft die Systemauslastung protokoliert werden soll. Dabei werden keine Snapshots (momentalen Aufnahmen) des Systems gemacht, sondern die Durchschnittswerte, gemessen zwischen 2 Protokollierungszeitpunkten.
Installation:
Step 1. Installieren
sudo apt-get install sysstat
Step 2. Aktivieren
sudo vi /etc/default/sysstat
change ENABLED=”false” to ENABLED=”true”
save the file
Step 3. Aufzeichnungsinterval von 10 zu 2 Minuten ändern:
vi /etc/cron.d/sysstat
Change
5-55/10 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
To
*/2 * * * * root command -v debian-sa1 > /dev/null && debian-sa1 1 1
save the file
Step 4. Restart
sudo service sysstat restart
Aktuelle Statistiken zeigen
#CPUs
sar -u
# Memory (RAM)
sar -r
#Netzwerk
sar -n DEV
sar -n DEV -s 15:43:00 -e 16:32:02
#IO
sar -b
Alte Statistiken zeigen
#CPUs
sadf -d /var/log/sysstat/sa18 -P , -s 16:44:00 -e 18:32:00
# Memory
sadf -d /var/log/sysstat/sa18 -- -r -s 16:44:00 -e 18:32:00
#Netzwerk
sadf -d /var/log/sysstat/sa18 -- -n DEV -s 16:44:00 -e 18:32:00
#IO
sadf -d /var/log/sysstat/sa18 -- -b -s 16:44:00 -e 18:32:00
wobei die Dateinamen wie 'sa18' können sich variiren.
Mehr Info
http://sebastien.godard.pagesperso-orange.fr/documentation.html
http://www.linupedia.org/opensuse/Systemueberwachung_mit_sysstat
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