Out of memory Issue in Tomcat

Description of Exception 
(Tomcat – java.lang.OutOfMemoryError: PermGen space)

The exception happens in web application deployment in tomcat.
Default settings memory space will not be adequate for some search information requirements.

If we check the tomcat error log, we might caught-up the issue as follows :

Solution for Linux environment

1) Find out catalina.sh file in tomcat bin folder
           
2) Check for class path settings.
    Use setenv.sh instead to run the environment variable
    Set as follows :

   CLASSPATH=
 
    if [ -r "$CATALINA_BASE/bin/setenv.sh" ]; then
     . "$CATALINA_BASE/bin/setenv.sh"
    elif [ -r "$CATALINA_HOME/bin/setenv.sh" ]; then
     . "$CATALINA_HOME/bin/setenv.sh"
    fi

3) Check for setenv.sh in tomcat bin folder
    Check if it is there, if not create manually and enter the following to it.

export JAVA_OPTS="-Dfile.encoding=UTF-8 -Xms128m -Xmx1024m -XX:PermSize=64m -XX:MaxPermSize=256m"

4) Restart Tomcat
   

Generating keytool  for SSL configuration in Linux Command 

• Navigate to the directory where we need to save your keystore file
• Then type the following commands in the shell

1. keytool -genkey -alias <name> -keyalg RSA -keypass changeit -storepass changeit -keystore keystore.jks
   (Note : Here name would be "tomcat" as default for the first time use.. If we need to create more than one keystore, then can use any name. If so, the name should be mentioned in tomcat server.xml)
2. keytool -export -alias <name> -storepass changeit -file server.cer -keystore keystore.jks
3. keytool -import -v -trustcacerts -alias <name> -file server.cer -keystore <path-to-jdk>/jre/lib/security/cacerts -keypass changeit -storepass changeit

•  Then change the tomcat "server.xml" accordingly
  <-- Define a SSL Coyote HTTP/1.1 Connector on port 8443 -->

  <!--
  <Connector 
             port="8443" maxThreads="200"
             scheme="https" secure="true" SSLEnabled="true"
             keystoreFile="<keystore saved path>.keystore" keystorePass="changeit"
             clientAuth="false" sslProtocol="TLS"/>
  -->

       
  (Note : If you are using different port for https access then change port accordingly in server.xml) 

•  Now we can access the deployed application securely. 
• Go to the browser and type

  https://localhost:<configured-port-number> ie: here it is 8443

Testopia and Bugzilla

Accessing Testopia

Any Bugzilla user can access Testopia by clicking on the "Product Dashboard" inside the main Bugzilla page

Products

The products in Testopia are imported from Bugzilla and are basically the products of the Yocto Project. These products can be seen in the left column of Testopia main page:

By clicking on a product you will see detailed description about it like the Test Plans it contains, the test cases and so forth.

---

Test Plans

• test plans are unique to the product they belong to and can not be shared between products.
• test plans contain all the test cases relevant to the product they belong to.

Test Cases

• test cases can not be shared between products.
• test cases can be shared between test plans within the same product.
• test cases have 2 special fields assigned to them: priority and category.
• test case priorities are linked to Bugzilla and affect bugs filed from the test case.

Test Runs

Test runs hold the results of how certain test cases fared in a specific build and environment. They are composed of Case Runs.

• test runs are unique to a specific product.
• test runs can not be shared between products.
• test runs are unique to the test plan they belong to.

Bug Life Cycle States:

• New - Potential defect that is raised and yet to be validated.
• Assigned - Assigned against a development team to address it but not yet resolved.
• Verified - The Defect that is retested and the test has been verified by QA.
• Closed - The final state of the defect that can be closed after the QA retesting or can be closed if the defect is duplicate or considered as NOT a defect.
• Reopened - When the defect is NOT fixed, QA reopens/reactivates the defect.

Bug Severity stages: 

Severity	Definition
blocker	Prevents function from being used, no work-around, blocking progress on multiple fronts
critical	Prevents function from being used, no work-around
major	Prevents function from being used, but a work-around is possible
normal	A problem making a function difficult to use but no special work-around is required
minor	A problem not affecting the actual function, but the behavior is not natural
trivial	A problem not affecting the actual function, a typo would be an example

Bug Priority levels:

• Urgent: Must to be fixed before any other high, medium or low defect should be fixed. Must be fixed in the next build.
• High: Must be fixed in any of the upcoming builds but should be included in the release.
• Medium: should take precedence over low priority defects and may be fixed after the release / in the next release.
• Low: Fixing can be deferred until all other priority defects are fixed. It may or may not be fixed at all.

Python+Regular Expression

By using Regular Expression we embed it into python-script and provide some string literals insearch of any pattern match with files.

Here we can question like "does the given string match with the pattern?"

Matching Characters

   '.'         Matches any character except a newline

   '^'                  Matches the start of the string

   '$'                  Matches the end of the string /  before the newline

   '*'                  eg: ha* will match ‘h’, ‘ha’, or ‘h’ followed by any number of   ‘a’s.

   '+'                  eg: ha+ will match ‘h’ followed by any non-zero number of ‘a’s

   '?'

*?, +?, ?? greedy match.where +,?,* looks for all possible matches of string  in entire text given.

   {m}    eg: a{6}will match  six 'a' characters not less than it

   {m,n}   eg: a{3,5} will match from 3 to 5 'a' characters.

   '\'      Escapes special characters ('*', '?').

   []     Indicate a set of characters  in a set:

     e.g. [amk] will match 'a', 'm', or 'k'

               

Fourth Week

Taking "diffs" for 2 files in linux:
               diff <path for file1><space><path for file 2>

Sourcing .sql files from a location to our db :
               1) scp <filename> user@hostip:<path to save this file in our machine>
               2) go to the file saved directory
               3) run mysql from that directory as : mysql -u root -p<password> and press enter
               4)select the database wher to source the files > use database; so now you moved into the database and then type "source <filename.sql>"

python
Reading file using python script
path = raw_input("Enter path to log file \n")
log = open(path)

In case of getting user input of a timestamp
yyyy,mm,dd,hh,mm = raw_input("Enter Start_Time in format(yyyy,mm,dd,hh,mm)").split(',')

use regular expression to get contents from a file
import re
re.search('^5', line)  ## this will get lines start with 5

python operations with "list"

eg : a=[66,333,333,1,1234] # a list of int
       print a.count(333) #result 2
       a.append(333)       #add element '333' to end of list
       a.reverse()             #reverse elements
       a.sort()                   #will give a sorted array of ascended values

python - defining a function and call function

eg: #print numbers in range which divisible by 2 and 3
#lets define a function def(fx)

def f(x): return x%2!=0 and x%3!=0
res=filter(f, range(0,1000))
print res