Dynamic Content Web Sites: Technologies & Scalability

transcript

Emmanuel Cecchetemmanuel.cecchet@inria.fr

LinuxWorld 2003 – San Francisco – Emmanuel.Cecchet@inria.fr 2

Dynamic content Web site

Web content is more and more dynamic

e-Commerce servers

Multi-tier architecture

Application protocol

Web server DatabaseApplication server

Client

Internet

Outline

TechnologiesPerformanceClusteringConclusion

Hypertext PreprocessorScripting languageModule integrated in Web server

Web server DatabaseClient

PHP example

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <body> <h1>Region list</h1> <?php $result = mysql_query("SELECT * FROM regions", $link) or die("ERROR: Request failed"); if (mysql_num_rows($result) == 0) print("<h2>Sorry, no region, db is empty.</h2><br>"); else while ($row = mysql_fetch_array($result)) { print("<a href=\"BrowseCategories.php?region=". $row["id"]."\">".$row["name"]."</a><br>\n"); } mysql_free_result($result); ?> </body></html>

Proseasy to learnideal for small projectswidely usedno strong typing

Consno strong typingcode maintenanceinterpreted languageexecutes in the Web server processad-hoc APIs for database access

Java Servlets

Java basedExecutes in a “Servlet Container”JDBC: unified interface for database access

Tomcat Servlet container

Web server DatabaseClient

Servlet server

h t t p d JVM

h t t p d

servlet

servletservletservletservlet

Java Servlet example

public class BrowseRegions extends HttpServlet{ …

public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException

{ out.print("<h1>Region list</h1>"); try

{ ResultSet rs = connection.createStatement().executeQuery("SELECT * FROM regions"); if (!rs.first()) out.print("<h2>Sorry, no region, db is empty</h2><br>"); else do

{ out.print("<a href=\"BrowseCategories?region="+rs.getInteger("id")+ "\">"+rs.getString("name")+"</a><br>\n");

} while (rs.next()); } catch (Exception e) { out.print("ERROR: Request failed for the following reason: " + e); return; } }}

What about JSP?

Java Server Pages Sun’s answer to Microsoft ASP“scripting for servlets”

Scripting languageCompiled into a Java servlet at the first

execution

JSP example

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <body> <h1>Region list</h1> <%

try { ResultSet rs = connection.createStatement().executeQuery("SELECT * FROM regions"); if (!rs.first()) { %> <h2>Sorry, no region, db is empty</h2><br> <% } else do{ %> <a href="BrowseCategories?region=" <%= rs.getInteger("id") %> "> <%= rs.getString("name") %> </a><br> <%

} while (rs.next()); } catch (Exception e) { %> ERROR: Request failed for the following reason: <%= e.getMessage() %> <% } %> </body></html>

Servlets/JSP

ProsOO programming (JSP for scripting)design patterns maturityJDBC for database accessServlet container independent from Web server

ConsWeb server / Servlet server communication limited number of servicesOO programming is more verbose (servlets)

J2EE Servers

Java 2 Enterprise EditionSeparation of presentation and business logics

J2EE Application Server

Web server DatabaseWeb container

EJB container

Presentation logic

Business logic

Client

Internet

J2EE Servers

Presentation logic JSP or Servlets

Business logicEnterprise JavaBeans (EJB)Entity Beans

database mapping BMP: by hand CMP: automatic

Session Beans stateless: temporary operations stateful: temporary objects (shopping cart)

Message Driven Beans asynchronous messages

Proswell suited for large projects or EAIpresentation and business logic isolation large number of services (transactions, security,

asynchronous messaging, clustering, …)

Consrequires skills

large number of specs impact of design on performances

complex to setupportability across servers to improve

Open-source offers

PHPimplementation from php.netincluded in Apache

ServletsTomcat (http://jakarta.apache.org/tomcat/)Jetty (http://jetty.mortbay.com)

J2EEJOnAS (http://jonas.objectweb.org)JBoss (http://jboss.org)

Outline

RUBiS Benchmark

online auction sitemodeled after eBay.com

9 open-source implementations PHPServlets7 EJB

all results are online

http://rubis.objectweb.org/

RUBiS – PHP & Servlets

Apache/PHP vs Apache/Tomcat

JVM Performance

200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600

Number of clients

JRockit

Design patterns: Servlets only

Presentation and business logic mixed

Database

Web container

Servlet

Presentation logic

Business logic

Servlet

Presentation logic

Business logic

Design patterns: Session Beans

Presentation and business logic separation

Session bean

EJB container

Business

Servlet

Web container

Servlet

Database

Presentation

Session bean

Business

Design pattern: Entity Beans

Data Access Objects separation with Entity Beans (BMP or CMP)

EJB container

Entity

Database

Entity

Web container

Servlet

Presentation

Business

Servlet

Presentation

Business

Design patterns: Session façade

Façade session bean with EJB 1.1

EJB container

Entity

Session facade

Web container

Session facade

Database

Entity

Business logic

Servlet

Presentation

Communication layer

Remote interface

Design patterns: EJB 2.0 local

Session façade with EJB 2.0 local interface Entity Beans

EJB container

Entity

Session facade

Web container

Session facade

Database

Entity

Business logic

Servlet

Presentation

Local interface

Code complexity

PHP Servlets-only

Sessionbeans

EB CMP EB BMP Sessionfaçade

EJB 2.0local

Business logic

Presentation logic

RUBiS - J2EE Servers

Apache/Tomcat/JBoss vs Apache/Tomcat/JOnAS

Session Beans EB-CMP EB-BMP Session façade EJB 2.0 Local

Optimized JBoss

Optimized JOnAS

J2EE Performance

Session Beans = Servlets >= PHPEntity Beans

BMP = CMPdata access very (too?) fine grain

Design pattern determines performance Communication layers : 45 to 90% cpu usageContainer designLess than 2% of execution time in user bean

Outline

Clustering

Internet

Web server

Client

Web server

Web serverServlet Server EJB Server

Servlet Server

EJB Server

DB Server

Servlet Server EJB Server DB Server

Servlet Server

EJB Server

DB Server

Web site Clustering

Load balancing on Web Servershardware: L4-switchsoftware

One-IP techniquesLVS (http://www.linuxvirtualserver.org/)RR-DNS

Servlet/JSP Clustering

Web server to Servlet serverLoad balancing with JK module (mod_jk)Static weighted round-robinSession affinity

Servlet/JSP server clusteringTomcat in-memory session replicationfailover ensured by mod_jk

EJB Clustering

Servlet/JSP to EJB serverclustered JNDIload-balancing and failover by cluster-aware

EJB Server clusteringcluster stubs for load-balancingtransparent failover for idempotent methodsbean state persisted in database

J2EE Clustering

Database clusteringCommercial offers

Oracle RAC (60.000$ / cpu)based on expensive SAN (Storage Area Network)

Open-source solutionsNo real clustering

– master/slave replication in MySQL– Postgres-R (still in alpha)

Database clustering

Performance scalability bounded by databaseLarge SMP are not commodityDatabase tier must be

scalablefault tolerant (high availability + failover)without modifying the client applicationusing open source databaseson commodity hardware

Redundant Array of Inexpensive Databases (RAIDb) better performance and fault tolerance than a single database, at a low cost, by combining multiple DB instances into an array of DB.

RAIDb controller gives the view of a single database to the client balances the load on the database backends

RAIDb levels RAIDb-0: full partitioning RAIDb-1: full mirroring (best fault tolerance) RAIDb-2: partial replication (best performance)

C-JDBC

Middleware implementing RAIDbTwo components

generic JDBC 2.0 driver (C-JDBC driver)C-JDBC Controller

C-JDBC Controller providesperformance scalabilityhigh availabilityfailovercaching, logging, monitoring, …

Supports heterogeneous databases

RAIDb with

Database Database

C-JDBC Controller Scalability - Fault tolerance - Failover -

Monitoring - Caching - Logging - ...

Database JDBC driver

DatabaseDatabase Database

Database

Java client program

EJB Container JOnAS, WebLogic,

JBoss, WebSphere, ...

Servlet container Tomcat, Jetty, ...

MySQL, PostgreSQL, Oracle, DB2, InstantDB, ...

Java client program

C-JDBC driver

EJB Container

JOnAS,

WebLogic, JBoss, WebSphere, ...

Servlet container

Tomcat,

Jetty, ...

C-JDBC driver

MySQL, PostgreSQL, Oracle, DB2, InstantDB, ...

C-JDBC

No scalability No fault tolerance

No failover

EJB Container

JOnAS,

WebLogic, JBoss, WebSphere, ...

Servlet container

Tomcat,

Jetty, ...

C-JDBC RAIDb-1 example

no client codemodification

original PostgreSQLdriver and RDBMSengine

C-JDBC providesscalable performanceand high availability

PostgreSQL PostgreSQL

C-JDBC Controller RAIDb-1

PostgreSQL JDBC driver

PostgreSQL

Java client program

C-JDBC driver

C-JDBC RAIDb-2 example

unload a singleOracle DB withseveral MySQL

add caching,fault tolerance,and monitoringfor free

MySQL MySQL

C-JDBC Controller RAIDb-2

MySQL JDBC driver

MySQLOracle

Java client program

C-JDBC driver

Oracle JDBC driver

TPC-W Performance

0 1 2 3 4 5 6

Number of nodes

Single DB

RAIDb-0

RAIDb-1

RAIDb-2

Outline

PHP, Servlets or J2EE ?

PHP: Apacheideal for small projectsno typing, ad-hoc APIs

Servlets: Tomcat/JettyOO programmingJDBC for database access

J2EE: JOnAS/JBossfor large projectsbusiness and presentation logic isolation large number of services

Clustering for scalability

Questions ?Apache/PHP/Tomcat: http://www.apache.orgJetty: http://jetty.mortbay.comJOnAS: http://jonas.objectweb.org/JBoss: http://www.jboss.orgRUBiS: http://www.objectweb.org/rubisLVS: http://www.linuxvirtualserver.org : http://c-jdbc.objectweb.org/

RUBiS – Overall results

Session Beans EB-CMP EB-BMP Sessionfaçade

EJB 2.0 Local

JBoss - Standard RMI

JOnAS - Standard RMI

JBoss - Optimized RMI

JOnAS - Jeremie

Dynamic Content Web Sites: Technologies & Scalability

Documents