INFO CENTER
Web Performance Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Active Monitoring — relies on the capability to send packets to servers and applications, and measure the service response obtained from the network. The volume and other parameters of the introduced traffic is fully adjustable and small traffic volumes are enough to obtain meaningful measurements. This provides a consistent and uniform system of measuring performance over time.
Alert — An automated way to send a person or another system a warning that a performance incident has occurred. See: Alerting, Dynamic Alert.
Alerting — The process of building and supporting alert and event management.
Application Performance Management — provides a means for measuring and analyzing an application’s quality of service as experienced by the end-user. With this perspective, a true end-to-end view of performance can be obtained across all components including application, desktop, network and server on a per user, per application, or per transaction basis. See: Internet Performance Management.
Availability — the ability of a component or service to perform its required function at a stated instant or over a stated period of time. It is usually expressed as the availability ratio, i.e., the proportion of time that the service is actually available for use by the customers within the agreed service hours.
Availability Management — is the ability of an organization to deliver consistent, predictable access to applications and data; providing a competitive business advantage to the enterprise.
B
Backbone — a high-speed network line or series of connections that forms a major pathway within a network. Usually provided by large Telecommunications or Internet Service Providers (ISPs).
Backbone Monitoring — measures Web page and transaction performance globally from major ISPs in real-time, enabling organizations to continuously monitor site availability and responsiveness.
Baseline — a snapshot or a position which is recorded. Although the position may be updated later, the baseline remains unchanged and available as a reference of the original state and as a comparison against the current position.
Benchmarking — allows companies to set appropriate goals, define their competitors, and compare availability and response times to processes and to peers in their industry.
C
Capacity Management — to ensure that the right amount of capacity is at the right location, for the right customer, at the right time and at the right price.
Change Management — process of controlling changes to the infrastructure or any aspect of services, in a controlled manner, enabling approved changes with minimum disruption.
Configuration Management — the process of identifying and defining the Configuration Items in a system, recording and reporting the status of Configuration Items and Requests for Change, and verifying the completeness and correctness of Configuration Items.
Connect Time — the time (in seconds) that it takes to connect to a Web server across a network from a client browser or Gomez agent.
Content Match — for Single URL and UTA tests, a user can define a specific string of characters that must appear in the source code of an HTML web page. If the match does not occur, usually this indicates a failed test.
Content Time — the time in seconds that measures the actual time to deliver content (images, HTML, or other objects) from the web server to the browser or Gomez agent.
D
Diagnostic Tools — are used to identify and resolve problems. They help test components, monitor resources such as performance, memory, processing power, undo changes made to files and etc.
DNS Error — When a browser or Gomez agent attempts to locate the test URL from a DNS server, the DNS server sends a error, and is not able to provide the IP address in the URL.
DNS Look-up — The process of calling a DNS server to lookup and convert a hostname to an IP address. For instance, to convert www.foo.com to 10.0.0.1.
DNS Server — A DNS server contains a subset list of certain IP addresses and hostnames used by all internet actions to convert the hostname or server name to the actual address of a computer on the internet (its IP address).
DNS Time — this component refers to the time it takes to translate the host name into the IP address.
Downtime — total time period that a service or component is not operational, within agreed service times. Also can be quantified as a percentage, such as 2% downtime.
Dynamic Alert — A dynamic alert allows for normal fluctuations in performance from different geographic regions to prevent an alert from being erroneously triggered. With the dynamic alert, each node’s alert status is assessed by comparing historical node performance with a current average. See: Alert, Alerting.
E
Error Codes — See appropriate web server error codes below.
- 0 Error (Server Error) — No connection to the server available or the server was unavailable.
- 300 Error (Multiple Choices) — The requested resource corresponds to multiple representations, each with its own specific location, and the negotiation information is being provided so that the user can select a preference and redirect its request to that location.
- 301 Error (Moved Permanently) — The requested resource has been assigned to a new permanent URL.
- 302 Error (Moved Temporarily) — The requested resource resides temporarily under a different URL. Clients should continue to use the URL since the redirection may vary.
- 303 Error (See Other) — The response to the request can be found under a different URL. The new URL is not a substitute reference for the originally requested resource.
- 304 Error (Not Modified) — If the client has performed a conditional GET request and access is allowed, but the document has not been modified.
- 305 Error (Use Proxy) — The requested resource must be accessed through the proxy given by the location field.
- 400 Error (Bad Request) — The request is not understood by the server due to an incorrect syntax.
- 401 Error (Unauthorized) — User authentication is required.
- 403 Error (Forbidden) — The server understood the request, but is refusing to fulfill it.
- 404 Error (Page Not Found) — The server has not found the URL requested.
- 405 Error (Method Not Allowed) — The method specified in the Request-Line is not allowed for the resource identified by the Request-URL.
- 406 Error (Not Acceptable) — The server is not sending a response that the requestor is willing to accept.
- 407 Error (Proxy Authentication Required) — The client must authenticate itself with the proxy (similar to Unauthorized).
- 408 Error (Request Timed Out) — The client did not produce a request within the time that the server was prepared to wait.
- 409 Error (Conflict) — The request was not complete due to a conflict with the current state of resources.
- 410 Error (Gone) — The requested resource is no longer available at the server and no forwarding address is known (similar to 404, but 410 is permanent).
- 411 Error (Length Required) — The server refuses to accept the request without a defined content-length.
- 412 Error (Precondition Failed) — The precondition given in one or more of the request-header fields evaluated to false when it was tested on the server.
- 413 Error (Request Entity Too Large) — The server is refusing to process a request because the request entity is larger than the server is willing or able to process.
- 414 Error (Request-URL Too Long) — The request entity is larger than the server is willing or able to interpret.
- 415 Error (Unsupported Media Type) — The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.
- 416 Error (Requested Range Not Satisfiable) — The request included a Range request-header field, and not any of the range-specifier values in this field overlap the current extent of the selected resource, and also the request did not include an If-Range request-header field.
- 417 Error (Expectation Failed) — The expectation given in the Expect request-header could not be fulfilled by the server.
- 500 Error (Server Error) — The client’s Web server is incapable of performing the request.
- 501 Error (Not Implemented) — The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.
- 502 Error (Bad Gateway) — The server received an invalid response from the upstream server that it accessed in attempting to fulfill the request.
- 503 Error (Out of Resources) — The server is unable to handle the request due to a temporary overloading or maintenance of the server.
- 504 Error (Gateway Timeout) — The server did not receive a response in time from the upstream server specified by the URL.
- 505 Error (HTTP Version Not Supported) — The server does not support the HTTP protocol version that was used in the request message.
End-to-End Performance — encompasses the collection of all components that make up a page including third-party content on off-site servers, graphics, frames, redirections, and so on.
End-user Monitoring — the ability to accurately measure the end-user experience of business processes and applications.
Event Management — the ability to manage dynamic, location-based events in real time, matching the right resources to the right situations, and ensuring in-field personnel have the information and support they require to affect optimal response.
Event Notification — empowers businesses to self-define dynamic and static performance thresholds so they know before customers when Internet application performance falls below optimal levels.
F-G
Financial Management — the management of the finances of a business/organization in order to achieve financial objectives.
First Byte Time — the time between the completion of the TCP connection with the destination server that will provide the displayed page’s HTML, graphic, or other component and the reception of the First Packet (a.k.a. first byte) for that object.
H
HTTP Test — runs the same test as Single URL testing, and provides response time details for each object on the page results for each object. Page results are broken down into: DNS Lookup, Connection Time, First Byte, Content Download, Redirect time.
I-K
Incident Management — the process of identifying, recording, classifying and progressing incidents until affected services return to normal operation.
Inside the Firewall — Referred to monitoring applications from inside a corporate firewall with a Private PEER or Agent instead of from the Backbone or Last Mile.
Instant Test — The capability of an operator to run a test in their GPN account against any node in the Gomez network and see the results of the test within a minute or two.
Internet Performance Management — The practice of monitoring and managing business processes and applications that are deployed on a TCP/IP network, but usually on the public facing Internet.
Internet Traceroute — A computer command that when executed tells how many hops (routers) are between a PC and another destination. It will also show the slowest connection point. See: Traceroue, Online Traceroute.
IT Service Continuity Management — investigates, develops and implements recovery options when an interruption to service reaches a pre-defined point.
ITIL — the OGC IT Infrastructure Library: a set of guides on the management and provision of operational IT services.
L-M
Last Mile — A Gomez service that provides end user monitoring across the globe from thousands of actual end user PCs. With the Last Mile service, organizations can run their tests to get true end user performance from broadband and dial-up users.
N
Node — refers to a unique combination of an agent’s geographic location, configuration and network provider.
NS Look up — an Internet utility that you can use to find the IP address of a host name or to find the host name that corresponds to an IP address by sending a domain name query packet to a designated domain name system (DNS) server.
O
Object Breakdown — The process of showing the individual performance components for each object in a web page. These components include DNS Lookup, Connection Time, First Byte, and Content Download.
Object Level Detail — The unique capability of the Gomez network to show the performance of each object in a web page.
Online Traceroute — displays the Internet route from the trace route server to the specified web site. See: Traceroute, Internet Traceroute.
Outside the Firewall — Usually refers to a monitoring capability outside of an organization’s local area network.
P
Page Download Time — the time it takes to download all the Web page’s objects and components.
Passive Monitoring — uses devices to watch end user traffic as it passes by. These devices can be special purpose devices such as a network sniffer or they can be built into other devices such as routers, switches or end node hosts. Examples of such built in techniques include Remote Monitoring (RMON), Simple Network Monitoring Protocol (SNMP) and netflow capable devices. The passive monitoring devices are polled periodically and information is collected (in the case of SNMP devices the data is extract from Management Information Bases (MIB)) to assess network performance and status.
Performance Event — An incident where a web site has a slow down or availability outage.
Performance Excellence — The methodology of rigorously maintaining a combination of people, process, and technology to achieve optimal returns on applications.
Performance Issue — An incident where a web site has a consistent or re-occurring slow-down or availability outage.
Performance Management — the continuous process of evaluating a system to determine whether the system can deliver the level of performance required, and then tuning it until it does. In a Web site environment, this basically means making sure the infrastructure of the site (hardware and software) can support the number of concurrent users with an acceptable response time.
Performance Problem — see Performance Issue.
Ping Test — an Internet utility that measures the time it takes for a host at a given address to receive and respond to a request.
Private Agent — allows companies to deploy their own GPN agents to test their Web applications from inside the firewall or from a partner/client location, and combine these results with similar tests conducted inform backbone locations via the Gomez Performance Network (GPN). The data is stored in the GPN database, which can be exported via XML, and can be viewed via a Web interface.
Problem Identification — allows companies to quickly determine the root cause of the problem so they can spend more time fixing, rather than finding, the problem.
Problem Management — process that minimizes the effect on the number of defects in services and within the infrastructure, human errors and external events.
Q
Query String — a data container appended to your URL address. Query strings provide a browser a way of passing information specific to the user to a particular web address. The host computer can parse the query string and send a customized result back to the browser.
R
Real Time Alert — A performance alert that is triggered immediately as a test passes a performance threshold, without any delay due to batch processing.
Release Management — the coordination of all the activities leading to and including product release to customers.
Response Time — elapsed time during performance measurement (usually end-to-end time.)
Root Cause Analysis (RCA) — Situational assessment and analysis seeking to isolate and determine the underlying factors that contribute to a specific performance problem.
S
Secure Sockets Layer Time — The time it takes to create an SSL TCP/IP connection with a web site.
Security Management — the process of managing a defined level of security on information systems and services. This includes firewalls, VPN devices, access control to servers, and configuration parameters on servers and desktops.
Server Error — the client’s Web server is incapable of performing the request.
Service Level Agreement (SLA) — written agreement between a Service Provider and the SLA customer(s) that documents agreed Service Levels for a service.
Service Level Management — the process of defining, agreeing, documenting and managing the levels of customer IT service, that are required and cost justified.
Service Management — management of services to meet the customer’s requirements.
Single URL — A description of monitoring a one page URL, such as http://www.foo.com.
Static Alert — A rigorously defined threshold for a performance alert, such as a response time value of 20 seconds or average availability of 95%.
Streaming Media — a method of making audio, video and other multimedia available in real-time, with no download wait, over the Internet or corporate Intranets. Streaming media consists of specially encoded video hosted on a streaming media server being viewed by a web audience through a streaming media player.
Synthetic Monitoring — The practice of using simulated end users to provide performance monitoring results.
T
Trace Route — an Internet utility that records the route that a packet of data travels between hosts. It is used to help identify which node on the network may be causing slowness along a given route.
Transaction — A Transaction is a test on a series or sequence of URL’s combined into one process. This offers you the ability to measure the performance of an online consumer’s experience navigating through an online shopping experience that requires multiple steps.
Transaction Failure — when a Gomez agent is not able to properly complete a transaction.
U
Uptime — the percentage of time that a web site is working.
UTA — Gomez’ Universal Transaction Agent that provides object and component level detail for all web-based interactions.
V-Z
Visual Traceroute — A graphical tool that displays the results of a traceroute, for instance, overlaid on a world map, to indicate the router paths the route takes.
