Apache Ignite - Distributed SQL ve Cache

Giriş

Açıklaması şöyle. Apache Ignite Java ile geliştirilmiş

Apache® Ignite™ was originally contributed to the Apache Software Foundation by GridGain Systems. The project rapidly evolved into a top level Apache project with tens of thousands of downloads per month. The GridGain Professional Edition, Enterprise Edition, and Ultimate Edition are built on Apache Ignite.

GridGain vs Apache Ignite

Açıklaması şöyle

Indeed, Gridgain is wraper built on top of Ignite. Gridgain gives you additional features such as Security, Rolling production update etc that is required for enterprise level application.

GridGain şirketi "Data Center Replication" da sunuyor

Neleri Destekler

Apache Ignite bir sürü şeyi birden destekliyor.

SQL

Key/Value

Transactions

Compute

Services

Streaming

Machine Learning

 Açıklaması şöyle

Apache Ignite is a high-performance distributed database that stores data in memory (as well as persistent).

As with every NoSQL solution, it supports replication and sharding out-of-the-box but also provides ACID transactions, SQL support, and Compute Grid.

Distributed SQL

Şeklen şöyle

Persistence

Ignite native persistence

Third party persistence

Durable Memory

Şeklen şöyle. Bir anlamnda Linux'taki swap dosya sistemine benziyor.

Maven

Şu satırı dahil ederiz

<properties>
  <ignite.version>2.10.0</ignite.version>
  <ignite.spring.data.version>1.0.0</ignite.spring.data.version>
</properties>

<dependency>
  <groupId>org.apache.ignite</groupId>
  <artifactId>ignite-core</artifactId>
  <version>${ignite.version}</version>
</dependency>

<dependency>
  <groupId>org.apache.ignite</groupId>
  <artifactId>ignite-spring</artifactId>
  <version>${ignite.version}</version>
</dependency>

<dependency>
  <groupId>org.apache.ignite</groupId>
  <artifactId>ignite-spring-data-2.2-ext</artifactId>
  <version>${ignite.spring.data.version}</version>
</dependency>

Örnekler

Gridgain örnekler burada

Bazı diğer örnekler burada

Bağlantı

Bağlantı için 3 yöntem var

1. Thick Client : Cluster topolojisine dahil olur

2. Thin Client : Cluster topolojisine dahil olmaz

3. JDBC : Relational Database olarak kullanmak istersek

Java

Şöyle yaparız. Herhangi bir düğüme bağlanmak yeterli

Class.forName("org.apache.ignite.IgniteJdbcThinDriver");
Connection con = DriverManager.getConnection("jdbc:ignite:thin://192.168.0.50");

In-memory data grid

Apache Ignite in-memory data grid özelliğine sahip olduğu için Hazelcast gibi Distributed Cache olarak kullanılabilir.

Embedded node

Apache Ignite embedded olarak yani aynı JVM içinde kullanılabiliyor. Eğer Spring ile birlikte kullanmak istersek açıklaması şöyle

The embedded node can be started by SpringCacheManager itself. In this case, we will need to provide a path to either the Ignite configuration XML file or IgniteConfiguration bean via configurationPath or configuration properties respectively.

Ignite Rest API

Açıklaması şöyle

Ignite provides an out-of-the-box HTTP REST client that gives us the ability to communicate with the grid over HTTP and HTTPS protocols using the REST approach. REST APIs can be used to perform different operations like reading/writing from/to cache, execute tasks, get various metrics and more.

To enable HTTP connectivity, we have addedignite-rest-http as a Maven dependency in our application. Explicit configuration is not required; the connector starts up automatically and listens on port 8080. We can also change the port by specifying -DIGNITE_JETTY_PORT=8081 as VM arguments.

We can check whether the rest API is working by using the below curl command.

curl 'http://localhost:8081/ignite?cmd=version'

Following is a sample GET REST API which we can be used to procure the data from the Cache using the CacheName and key.

http://localhost:8081/ignite?cmd=get&cacheName=student&key=1

Anotasyonlar

@QuerySqlField

 Alanın Ignıte tarafından görülebilmesini sağlar

@AffinityKeyMapped

Foreign key olarak bağlı iki tablonun collocated olmasını sağlar. Satır sayısı az olduğu için Collocated yapılamayan tablolar, replicate edilmeli

SQL Dili

ANSI 99 uyumlu

INSERT 

UPDATE

DELETE

CREATE TABLE

DROP TABLE

CREATE INDEX

DROP INDEX

ALTER TABLE

SELECT : JOIN ve SUBQUERY 

yapılabilir

ALTER TABLE

Şöyle yaparız

ALTER TABLE city ADD COLUMN IF NOT EXISTS population int;
ALTER TABLE person DROP COLUMN (code,gdp);

CREATE INDEX

B+ Tree Index kullanır. Inline veri büyülüğü belirtilebilir.

CREATE TABLE

CREATE TABLE yazısına taşıdım

SELECT

Örnek

Şöyle yaparız. country ve city diye iki tablo var. Burada "Collocated Join"  önemli. Collocated yan yana demek. Non-collocated join'ler ciddi performans kaybına sebep olabilir.

SELECT country.name, city.name MAX(city,population) as max_pop
FROm country JOIN city on city.countrycode = country.code
WHERE country.code IN ('USA','RUS','CHN')
GROUP BY country.name, city.name ORDER BY max_op DESC LIMIT 3;