Veriton. Getting the Best out of Hardware Load Balancers in an Oracle Environment. What is a Load Balancer? Agenda. What s out there?

Transcription

1 Getting the Best out of Hardware Load Balancers in an Oracle Environment Simon Haslam Veriton Limited Veriton Oracle Partner, established 13 years Demanding web & call-centre applications Oracle ias & Logic (clusters, JEE, ADF,, OID, Reports, etc) Database & related technologies (Solaris/Linux, load balancers, firewalls, ) 1 (1.2) 2 (1.2) Agenda 1. Architecture 2. Configuration 3. Monitoring 4. Common Problems What is a Load Balancer? 1. A device to evenly balance load across servers (doh!) 2. A device to redistribute load in case of component failure 3 (1.2) 4 (1.2) The Big Names What s out there? Popular Brands Software Alternatives 5 (1.2) 6 (1.2) 1

2 Host OSI Model & IPS 7 Application 6 Presentation 5 Session HTTP, TLS/SSL, DNS, LDAP, SSH, SNMP Application Mid Tier App Serv Architecture: Base Install 4 Transport TCP, UDP Transport Media 3 Network 2 Data Link IPv4/v6, ICMP, IPsec (routing) e.g. MAC address Internet Link OID 1 Physical CAT-5E Databases 7 (1.2) 8 (1.2) Load Balancer Typical HA Mid Tier App Serv Mid Tier App Serv Load Balancer Databases Instances OID OID RAC Workload Distribution Databases Database Instances Oracle IdM Enterprise Deployment Guide 9 END (1.2) 10 (1.2) Configuration Concepts Details Logical / virtual layer Physical server layer Monitoring URL switching Session persistence/stickiness Cookie insertion Routing Algorithms Notes Text config. vs browser-based Management network 11 (1.2) 12 (1.2) 2

3 Example Basic Configuration (e.g. ) Example: Virtual (BIG-IP) sso1.dmz.veriton.com : 7777 Load Balancer sso2.dmz.veriton.com : 7777 virtual psso { destination :http ip protocol tcp persist cookie pool psso-pool Serv Typically you d have SSL acceleration on the Virtual too 13 (1.2) 14 (1.2) Example: (BIG-IP) Example: Virtual (CSS) pool psso-pool { member :7777 member :7777 content psso vip address protocol tcp port 80 add service psso01 add service psso02 string prefix "LBR=" sticky-inact-timeout 1440 advanced-balance arrowpoint-cookie redundant-index 500 Typically you d have SSL acceleration on the Virtual too 15 (1.2) 16 (1.2) Example: (CSS) Monitoring service psso01 ip address port 7777 Heath monitor / Keep-alives Test methods & intervals: service psso02 ip address port 7777 HTTP (URL) OC4J (URL) (URL) OID (LDAP bind or search) Reports (URL to rwservlet) Timeouts & retries 17 (1.2) 18 (1.2) 3

4 Layering of Timeouts Load Balancing Common Oracle Middleware Components Can t afford to maintain sessions indefinitely load balancers may not be rebooted for year+ Want predictable service degradation & failures OHS OC4J app Logic OEM ASC WLS Admin Console Reports OID Forms not really 19 (1.2) 20 (1.2) Example: (CSS) Example: (BIG-IP) service psso01 ip address port 7777 keepalive type http keepalive uri "/sso/status" keepalive maxfailure 1 pool psso-pool { monitor sso_http_monitor member :7777 member :7777 monitor sso_http_monitor { use http interval 5 timeout 5 send "GET /sso/status HTTP/1.0 recv "OC4J_SECURITY is running." 21 (1.2) 22 (1.2) Diagnostics & Monitoring Service diagnostics HTTP: named cookies are useful VIP/server status info on the LB Central status screen SNMP traps Use your favourite network monitoring tool OEM plug-in, e.g. for BIG-IP Port mirroring / sniffing Document LB Configuration! 23 (1.2) 24 (1.2) 4

5 ❹Common Problems: Technical Monitoring nothing very useful Monitoring the wrong thing or level Too long failure timeouts Too many failures allowed before failure overloading servers ❹ Common Problems: Politics People spend a lot of money on hardware, but not on staff training / consulting to configure it infrequent / one-off management lack of understanding / sales hype certification / status Effective solution requires close cooperation from different teams may be outsourced network support ineffective monitoring may mean finger pointing Iterative process (+ minimal docs) needs testing time! 25 (1.2) 26 (1.2) ❹ Please be polite! Always provide a Sorry/Unavailable page Store on LB vs separate web server Useful to tell people when service may be back Should be more common! 27 (1.2) 28 (1.2) ❹ More Advanced Topics SSL offload/acceleration (very common) Load balancing scheduling algorithms HTTP compression HTTP caching Ramp-up times Fall-back servers Scripting (e.g. irules) Geographical Load Balancing (e.g. activeactive or DR sites) Summary LB are integral part of HA solution Understand what you re balancing Work closely with your network team Don t get fobbed off with defaults Be careful about timeouts Allow time to fettle configuration deliver the level of HA your management expects! 29 (1.2) 30 (1.2) 5

6 Any questions? Thank you for listening! OFM blog: simonhaslam.co.uk 31 (1.2) 6