Monday, March 3, 2014

Redis Performance Evaluation

Redis is an open source, BSD licensed, advanced key-value store. Recently I came across few projects that support redis as their storage. So I think lets explore it a bit more. 
Evalution of redis becomes more easier as it provides a support of redis-benchmark.

Lets see what was result for me. 

System Details : Core 2 Duo , 32-bit, Centos 6.5.

All operations are performed with no pipeline. 

  • Set Operation Performance:

  • Get Operation Performance

  • LPush Operation Performance

  • LPop Operation Performance

Redis perfomed quite well , but how much the performance will get affected on the use of jedis (java client for redis). That will be discussed in next blog.

Sunday, March 2, 2014

Drools Performance Benchmark

Drools performing well in standalone mode, rate is ~ 114285 records/sec for state-full session and ~4760 records/sec for stateless session. Standalone mode refers to just triggering rules on records. There no integration with camel, spring or any other framework.

Have a look on graph for more details:

Statefull vs Stateless session over 1 rule

Statefull vs Stateless session over 10 rule

Performance comparison on 32 bytes, 64 bytes & 128 bytes java object

Note: Performance is almost same for larger java object the variation is due to limitation of java heap memory of VM

Monday, February 10, 2014

Dynamic Drool.

I recently came across a rule engine called drools . Drool 6.0 is quite different from its previous version. For more information you can have a look here.

I am currently working on a use case scenario in which I want the rules to be updated from my webapp (lets call it a drool-workbench) such that new rules can be applied on new tuple of an input stream without building the source again.

Consider this:

Suppose there is an input stream of tuple1,tuple2 & tuple3, and a rule that can be applied on these tuples.
Now, rule r1 is applied on tuple1 & tuple2. And then we need this rule to be updated with some new conditions. With the help of web-app (drools-wb) the rule r1 can be modified as per need. And then the latest artifact in maven repository can be deployed by "build and deploy" feature of drool-wb. As a new tuple (tuple3) is inserted into the stream, kieScanner will scan the maven repository for latest artifact and modified rule will be triggered on tuple3.

Sample Code:

package com.drool;


import org.kie.api.KieServices;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.kie.api.builder.ReleaseId;
import org.kie.api.builder.KieScanner;
import sample.sample.Person;

public class Dynamicdrool{
 public static void main(String [] args){

  BufferedReader in = new BufferedReader(new InputStreamReader(;
  String s;

  KieServices ks = KieServices.Factory.get();
  ReleaseId releaseId = ks.newReleaseId("sample","sample","1.0-SNAPSHOT");
  KieContainer kc = ks.newKieContainer(releaseId);
  KieScanner kScan = ks.newKieScanner(kc);

   while((s = in.readLine())!=null && s.length()!=0)
    Person p = new Person();
    KieSession ksess = kc.newKieSession("sampleKs");
  }catch(IOException e){

Points to remember:
  • Use maven build in your project, to be able to use maven repository.
  • KieScanner plays an important role, and it generally scans for newer versions in repository.
    So use 1.0-SNAPSHOT as version or configure your maven for incremental version.
  • There is a bug with kie-Scanner in 6.0.1-Final build. Either wait for latest release or build repos from master branch

Thursday, August 22, 2013

Drop Table functionality in AlsoSQL(JsonServer plugin of Drizzle)

Do you want to drop table just with the help of json. Now you can do that , recently I have added drop table functionality with json_server plugin.
If you check with Drop table syntax in SQL. You can use drop table in various ways:
  • Drop Table.
  • Drop Table If_exists.
  • Drop Temporary Table.
Json Server allows to drop table in first two ways only.

How you can drop a table?

Its really simple, just start drizzled server with json_server plugin enabled.And then send a curl request to drop a table.

Here is a demo version:
  • Create a schema name as "json" and a table "test" in drizzle database.
  • Now send a HTTP request to drizzle server.
  • curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"schema_name":"json","table_name":"test"}}' 'http://localhost:8086/json/ddl/table/drop'
  • HTTP Response.
  • {
       "sql_state" : "00000"
  • Send a HTTP request for "DROP TABLE IF_EXISTS [TABLE_NAME]"
  • curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"schema_name":"json","table_name":"test","if_exists":"true"}}' 'http://localhost:8086/json/ddl/table/drop'
  • Response should be:
  • {
       "sql_state" : "00000"
Drizzle internals doesn't allow identifier::Table to drop a table, they use TableList. So Overload a function with identifier::Table as parameter works for me.

Branch related to this work: lp:~mohyt/drizzle/json_server_table

Sunday, July 28, 2013

Beware to say "Treat warning as an error" in new GCC

Are you building your something using Gcc(>=4.6) ?
If yes, then you used be more careful to use "treat warning as an error".
Recently I tried to build zbase over Ubuntu 12.04 2 which uses Gcc (4.6.2) and I faced lots of problem.
And then I moved to Gcc(4.2), everything was too smooth. No error or warnings.

Then I looked into Gcc release details and came across with few important points:

  • -Wunused-but-set-variable and -Wunused-but-set-parameter warnings were added. Also the -Wunused-but-set-variable warning is enabled by default by -Wall flag and -Wunused-but-set-parameter by -Wall -Wextra flags.
  • Also you may face few linkers problem. I faced a one with jemalloc.
For more about changes have a look here :)

In drizzle , I have to include "config.h" in each file to get rid of this type of error.

Tuesday, July 23, 2013

Setting Up a Drizzle Development Ubuntu Box

Sometimes we just get bored to figure out dependencies for drizzle development.
Ubuntu have a drizzle-dev package for development purpose. But for me it's not sufficient.

I follow this particular steps for box setup:

  • Get Ubuntu 12.04 or whatever you like, install it on virtual box.
  • Now after setting up Ubuntu VM-Box. Open terminal and type:

    sudo apt-get install bzr drizzle-dev autopoint libboost1.48-all-dev libprotobuf-dev protobuf-compiler uuid-dev libcloog-ppl
  • Also you can try apt-get build-dep drizzle
  • Now compile source as mention here.

Thursday, July 4, 2013

What's new in Json Server ??

As a part of Drizzle , I just started changing the internals of JSON Server with the help of Stewart.
So, what's new ? . That is a big question for this plugin. Last time I did some re-factoring and implemented some new functionalities. Right now I am not focusing on functionality part too much. But yeah, plugin will come up with some new functionalities soon.

Previous version is capable of basic functionality like Insertion, deletion , selection etc. For more details look here. In previous versions , we generate a sql query by parsing json request and then execute that query with the help of Execute API. But Execute API restricts some functionality.

So I just tried to perform sql execution without Execute API. Now we just parse json query and uses parameter with Storage Engine API.

Right now we have two functionalities with such implementation:
  • Create Schema
  • Drop Schema
If you like to play with this, try out this branch (lp:~mohyt/drizzle/drizzle-json_server) .

How to play with it? , its too simple :
  • Start your drizzle server with json plugin enabled (./drizzled/drizzled --plugin-add=json_server)
  • Now send a curl request to create schema. For example,
 --exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:8086/json/ddl/schema/create'
  • And , to drop a schema , try this ,  
--exec curl -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"query":{"name":"json"}}' 'http://localhost:8086/json/ddl/schema/drop'

Comments are most welcome :)