https://github.com/sandysanthosh/java-performance-problems

Top Common Problems Occures in Java and Tools to be used
https://github.com/sandysanthosh/java-performance-problems

performance-analysis

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Top Common Problems Occures in Java and Tools to be used

• Host: GitHub
• URL: https://github.com/sandysanthosh/java-performance-problems
• Owner: sandysanthosh
• Created: 2018-04-29T04:09:32.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2020-04-17T17:08:53.000Z (over 5 years ago)
• Last Synced: 2025-02-28T20:57:46.574Z (11 months ago)
• Topics: performance-analysis
• Homepage: https://sandysanthosh.github.io/Java-Performance-Problems/
• Size: 8.79 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

          
# Java-Performance-Problems

#Top Common Problems Occures in Java and Tools to be used

minimise memeory:

lazy allocation of collection

-dnt create something until u need to put something into it

dnt create colleciton in single object

-just store the object itself

size collections correctly

only 2 size put it correctly

HashMap mhy = new HashMap(2);

avoid expansion of large collections due to 2x algorithm

32 MB used to store 17MB of data

colloections do not shrink once expanded

may be reallcoation if collections uses drops

latency:

how long does gc event takes.

stats:

exception-error with app

app time per request -

data base response time

active thread state

time spent in gc

memory allocation

gather the stats:

LOGS

profiler

core jdk tool

jmx metrices

apm-application performance monitorgin tools

framework/app server moniroting tools

data does each tool provide?

logs

app server monitoring

new relic

yourkit

jvisualkit

jconsole

jmap/jhat

-->jstack

new relic:

applcation permonance monitoring(apm)tool 

that monitor web app,servers,database

donitostics paid

-->jmap/jhat

use in production:

logs

jconsole

app server monitoring

jvisualVM-

jstack

new relic

new relic:

saas

angular react and ember

legicy:

migrating web logic to cloud

lift and shift

appliacation sernver technology

not pizza delivery company software company

memeory utilization

servers

mobile

browser

plugins

new relic:

application monitor 

performance of mobile

for end perspective

performance servers

performance broser

performance platform

new relic works:

deploy new relic agenet in your apps

new relic collect app health data

app performance anywhere

external web calls

web and non-web

highest salary from employee:

select * from employee

where salary = (select max(salary) from employee);

max salary:

select max(salary) from employee;

second highest salary from employee:

select max(salary) from employee where 

salary not in (select max(salary) from employee);

select range based on employee id:

select * from employee where employee_id between 2003 and 2008;

select e.employe_name ,e.salary,d.depart from employee e

inner join department d on (e.depart_id=d.depart_id) where

salary in (select max(salary) from employee);

most common problesm:

slow database queries

ineffiecent applcition code

too many db queries

concurrency issues

memeory leaks

configuration issues(pooling threshold, request throttling)

slow db

GC pauses

memory churn

dbqureies,

memory leaks,

gc puses

->resources leaks:

forgetting to close() resources

jdbc connections

file handles

->gc login:

->Heap Dump Analysis:

 eclipse memory analuzer- eclipse MAT

 for dumps ,not histograms

  -histogream can convert into spreadsheet data easily

->memory leaks:

 -> profiler:

  -> memory: 

    -> generation count

profiler:

execution profliling

memory profiling

thread visualization

heap visulization

sampler:

sample:

 CPU

JDBC:

 JDBC is dsigned as a layout plugin component

 excellent for plugging in logging layer

->JDBC

->can plugin your own layer

->catch commication in either direaction

->monitoring

->logging

->caching

->JDBC:

JDBC logging layer

P6Spy is a framework that enables database data to be seamlessly intercepted and logged with no code changes to the application.

->concurrency:

try to determin what code is:

blocked

waiting

sleeping

the results will ne easily identified with thread dumps

but don't dump too often

concurrency:

stack traces alredy lists deadlocks

stack traces show synchorinzed locked monitors

top common problems:

slow database queires-JDBC monitoring(eg p6spy), tune sql

inefficent application code- execution profile(jvisualvm), tune code

too many db quries-jdbc monitoring(p6spy), refactor calls

commcurrency issues-stack trace analysis

memorry leaks-heap dump analyser(eclipse MAT),identify the objects retaigning memory and fix the code to stop that

configuration issue(pooling thresolds,request throtting)-keep record to changes

slow DB-JDBC monitoring(p6spy), find clusters or slow queries

GC pauses-gc logging and gc logs analyzer(gc viewer)

memeory-look for object allcoation in memory profiler(jvisualvm)

buiulding and tuning high performance java platforms:

web portals

middle wware

database

batch/data movement

proifling java code with jprofile:

->run as

->run configuration

->jprofiler->download

->install and start

memory view

cpu view

->session

->new session

->launch

->main classes->browser class file

->click ok

->general settings->

->cpu views

->program will run for few seconds

->record memory

->hot spot -> how much amount of memeory uses

cpu profiling:

->Two Types:

->instrumentation  -> all  types

->sampling   -> cpu profiling

filter settings:

filter rule for method call recording