Extreme Networks Px Series manual Health Checks, Overview

Page 99

9Health Checks

This chapter describes health checks you can use to ensure that a given application is running on a real server before sending user requests to that server. The chapter contains the following sections:

•Overview on page 9-1

•Health Checking Procedure on page 9-3

•Configuring Health Checks on page 9-4

Overview

Because each application works differently, the application switch supports the following types of health checks:

•ICMP Ping— Ensures that the host is reachable. In general, this does not provide any information about application health, but provides the simplest check.

•TCP Open —Opens a connection to a specified TCP/IP port. Optionally, the application switch can compare the response sent upon open to a preconfigured string to further ensure that the application responded correctly.

•HTTP GET — Sends an actual “HTTP GET” request to the server. Optionally, the application switch can compare the response sent upon open to a preconfigured string to further ensure that the application responded correctly.

Px Series Application Switch Installation and Configuration Guide

9-1

Page 98 Page 100
Image 99
Page 98 Page 100
Contents Published April Part number 100101-00 Rev Page Contents Installing the PxM Application Switch Module Configuring Servers and Services Index Index of Commands Introduction PrefaceConvention Description ConventionsText Conventions Icon Alerts you toRelated Publications Preface Purpose of Server Load Balancing Server Load Balancing Concepts1Conceptual view of server load balancing TermsLayer 4 Load Balancing Load Balancing Modes2Single client-server transaction using layer Layer 7 Load Balancing and Content Analysis3Establishing a layer 7 request Port Rewrite Getting Started on Load Balancing ConfigurationGetting Started on Load Balancing Configuration Page Installing the SummitPx1 Application Switch Overview of the SummitPx1 Application SwitchSummitPx1 Front View Color Indicates 1Px series application switch LEDsTo DB-9 SummitPx1 Application Switch Rear ViewSignal Description 2DB-9 Adapter PinoutsInstalling the SummitPx1 Application Switch Determining the LocationRack Mounting Free-Standing Powering On the SummitPx1Setting Up Console Communication Configuring Switch IP Parameters Configuring the 10/100 Ethernet Management Port Installing I/O Modules Installing the PxM Application Switch ModuleRemoving I/O Modules Removing I/O Modules Page Managing the Switch 1Command Syntax Symbols Using the Command-Line InterfaceAbbreviated Syntax and Command Completion Syntax Symbols2Line-Editing Keys Symbol DescriptionLine-Editing Keys Specifying Text ValuesConfiguring Management Access Command HistoryPrompt Text Changing the Default Passwords Modifying Accounts Creating AccountsManaging the PxM Command DescriptionConfiguring VLANs Contact Configuring Snmp4SNMP Configuration Settings Setting Description SystemSettingDescription Configuring DNS Client Services5DNS Client Configuration Commands Using Secure Shell 2 SSH2Config ssh2 key Enabling SSH2 for Inbound Switch AccessUsing SCP2 from an External SSH2 Client SSH2 Client Functions on the Switch Utilities Showing CPU LoadChecking Basic Connectivity Logging Starting the GlobalPx Content Director Agent Configuring a Startup Banner MessageInternet DNS server Example ConfigurationFollowing commands configure all system-related facilities Page Configuring Real Servers Configuring Servers and ServicesConfiguring Server Groups Configuring Virtual Services Layer 4 Port-based Load Balancing Layer 7 Virtual ServicesConfiguring Traffic Tagging Configuration Example 1Tag SpecificationsTag Specification Description Tag Range Configuration Example Page Scheduling Policies Choosing Policies, Persistence Modes, and NATPersistence Modes 1Scheduling PoliciesSpecifier Policy Description UDP Flow Persistence Client IP Persistence Mode1Client IP persistence mode Cookie Persistence Modes Configuring Client IP Stickiness2Self-identifying cookie persistence mode Persistence Modes Hashed Cookie Persistence Session Learned Cookie Persistence Mode 4Learned cookie persistence mode Configuring Cookie Stickiness SSL Session Identifier Persistence NAT Modes Full-NAT ModeConfiguring Full-NAT Mode and Proxy IP Addresses Server-only Half-NAT ModeConfiguring Half-NAT Mode Config source-flow name next-hop gateway-mode ip Real Syslog server SummitPx1 Configuration Example Page Domain and URL Switching URL Switching1Typical switching scenario Domain Switching2Domain switching example URL Switching Configuring URL Switching3Simple URL switching example 4More Complicated URL switching example 5Hierarchical approach to pattern rules Creating Domain and URL Switching Rules 1Wildcard CombinationsWildcard Example Definition Modifying Existing URL Rules and Domains Application Servers Management net Configuration Example Page Using Vrrp with the SummitPx1 Configuring RedundancyGive backup systems lower priorities Adding and Configuring VRRPsUsing Vrrp in Existing Redundant Networks Vrrp Automatic Synchronization 1Application switch using multiple VLANsFollowing commands can be passed from master to backup Using Esrp with the PxM Configuring Redundancy for the PxMFor SW2 Configuring the PxM for Multiple VLANsConfiguring a Default Gateway Overview Health ChecksServer Startup Pacing Health Checking Procedure Configuring Health Checks Timers and CountersTypes of Health Checks You can disable health checks for a server group Page Monitoring the Switch 1Statistics Display CommandsShowing Traffic Statistics Displays packet-level counters for 2Configuration Display Commands Showing Configuration DetailsConfiguration Displays SummitPx128 # show server details Status DisplaysColumn Description Show health Information5Management and Troubleshooting Commands Managing and Troubleshooting OperationCommandDescription Esrp IndexHttp GET AUX Page Index of Commands
Top Page Image Contents