Proxy Servers: Basics and Resources

A proxy server is a service that provides authentication and mediation between database or publisher websites and the end user by routing Internet traffic through its system.

Why learn about proxy servers?

A proxy server is a service that libraries use to authenticate their users to provide access to many online databases and publisher websites.  Using a proxy service allows library resource vendors to authenticate users from a single point-of-access regardless of where they are located, on-campus or from their home computer.

The Basics

For our examples, we’ll use the popular EZproxy product from OCLC.

Authentication

To avoid having to provide users with an individual or institutional login and password, most database and publisher websites authenticate users by IP address.  Sometimes vendors will limit access to a range of IP addresses—on a single campus, for example.  But for users outside of the physical campus, you must provide a known IP address (or set of IP addresses). This is accomplished by routing users through a proxy server so that the access requests come from its IP address(es) which are recognized by the vendor.  The content is then returned to the proxy server and routed back to the original user.

EZproxy process
Source: http://www.oclc.org/support/services/ezproxy/documentation/learn/overview.en.html

Because libraries can’t let everyone access their resources via EZproxy, they must authenticate their users before access.  EZproxy allows user login itself, but EZproxy also provides a method of authentication using your institution’s single sign-on (SSO) server.

Resource Access

EZproxy is accessed using an HTTP request.  To access a website via EZproxy, you must prepend the EZproxy server URL to the database or publisher’s website address.  A typical EZproxy URL looks like this:

http://ezproxy.yourlib.org/login?url=

To this proxy URL, we add the URL for the website we wish to access through EZproxy. For example:

http://ezproxy.yourlib.org/login?url=http://www.credoreference.com

The above URL is referred to as a “pre-proxy” link.  Once a website is accessed via EZproxy, the address changes to a “post-proxy” URL.  For example:

http://search.credoreference.com.ezproxy.yourlib.org

As you perform a search or click on links on a database or publisher site, you are submitting your requests to your EZproxy server which passes them on to the original website.  Data is returned to the EZproxy server which sends it back to your browser.  That is why the post-proxy URL ends with .ezproxy.yourlib.org (ignoring the path).

You might notice some post-proxy URLs use hyphens instead of dots between parts of the original website’s address.

https://refworks-proquest-com.ezproxy.libproxy.db.erau.edu.

The short explanation is that the EZproxy server uses a wildcard security (SSL) certificate for *.ezproxy.yourlib.org which allows one subdomain before the EZproxy server domain (ezproxy.yourlib.org).  The hyphens “trick” the server into seeing the original website as a single subdomain. This is done only for original websites that use HTTPS.

EZproxy Configuration

EZproxy has many settings that are configured during initial installation (using hyphens with HTTPS, for example).  You also set the maximum number of virtual hosts (typically from 5,000 to 20,000).

For each resource you access through EZproxy, you must configure it separately in a block of code called a stanza.  In the stanza for a database or publisher website you must specify at the minimum a Title (T) and starting URL (U).  Other basic stanza directives are Host (H), HostJavaScript (HJ), Domain (D), and DomainJavaScript (DJ).  Below is a basic database stanza:

Title SPIE Digital Library
URL  http://www.spiedigitallibrary.org
DJ   spiedigitallibrary.org

The Title directive is used to identify the resource (and is used for the link text on the default EZproxy list page).  The URL is used to match the EZproxy request link with the appropriate stanza to apply.  Once accessed, any further links on the resource site will be compared to any D or DJ lines and if there is a match, will be proxied and given access (including any JavaScript if a DJ line is encountered).

If a database or publisher website includes multiple domains or subdomains or uses both HTTP and HTTPS, you need to add Host (H) or HostJavaScript (HJ) directives to account for them.  More advanced directives are used to manage website cookies, set domains that should never be proxied, find and replace HTML code, and many others.  OCLC publishes an EZproxy Reference Manual to list these directives.

Here is a more advanced database stanza:

Option DomainCookieOnly
Title Engineering Village
URL http://www.engineeringvillage.com
HJ https://www.engineeringvillage.com
HJ engineeringvillage.com
HJ www.engineeringvillage.com
HJ www.engineeringvillage2.org
HJ www.ei.org
HJ acw.elsevier.com
DJ ei.org
DJ engineeringvillage.com
DJ referexengineering.elsevier.com
Option Cookie

OCLC publishes a list of recommended database stanzas for many of the most popular databases.  Of course, websites are frequently updated and these changes often require revised or completely new stanzas.  These stanzas are found in the config.txt file.

Resources

Here are some resources to learn more about EZproxy.

 

Library Service Status Pages

Online library services play a vital part in providing access to library resources and services.  Thus, it is very useful for library staff to know the status of these third-party services.  Downtime is rare, but when staff and users need to know the availability of online services, having a library service status page can be extremely helpful.  Fortunately, library vendors know this and increasingly are providing access to websites for displaying current service status and notices of planned interruptions.

Here is a list of the known major library service status pages:

bepress

bepress Current Statusbepress supports institutional repositories with Digital Commons, SelectedWorks, Expert Gallery Suite, and ExpressO online manuscript delivery service.  Their website has a Current Status page that covers all of these services including status details, scheduled maintenance, and recent product updates.

Access the bepress Current Status page.

EBSCO

EBSCO Help Alerts

On its EBSCO Help website, the company provides News and Alerts for its wide range of databases and EBSCO Discovery Service (EDS).  You can enter your email address to subscribe to alerts, as well.

Access the EBSCO Help Alerts page.

Ex Libris

Ex Libris System Status

With the merger of Ex Libris and ProQuest, Ex Libris took over the support of all library systems and discovery services.  The company has created a unified system status page for Alma, Summon, Serials Solutions 360 Link, Intota, Primo, SFX, and more.

Access the Ex Libris System Status page.

OCLC

OCLC System AlertsFrom the OCLC Support & Training website, you can access OCLC System Alerts.  This blog-like site reports current and past maintenance and issues for services including Connexion, hosted EZproxy, WorldCat, and WorldShare products.

Access the OCLC System Alerts page.

SirsiDynix

SirsiDynix Status

SirsiDynix is a major library vendor with cloud-based systems such as their BLUEcloud services.  The company’s status page contains notifications of scheduled maintenance and outages by region.

Access the SirsiDynix Status page.

Springshare

Springshare Systems Status Dashboard
Source: Springshare http://www.screencast.com/t/fs0G5Y5yu

Springshare understands the importance of providing status information for library resources and services to library users.  That’s why they created the Systems Status Dashboard in LibAnswers that allows your library to set up and display the status of your website, LibGuides, local resources, and databases.  You can alert users to any planned system maintenance and explain unexpected downtime.  For any LibAnswers site that has enabled the public status dashboard, you can view it by adding /systems after their LibAnswers URL.  Some examples are Manchester Metropolitan University, the University of Maryland Libraries, and Georgia College.

Read more about the Springshare Systems Status Dashboard.

TwitterIn addition to bookmarking the above sites, follow your important library vendors on Twitter.  That is where they will often post the first announcements of issues and further status reports.

Discovery Services: Basics and Resources

A discovery service is an online library searching tool that provides an all-in-one interface for finding both local library items and online subscription and open access resources.

Why learn about discovery services?

Most libraries use discovery services in addition to, or as a replacement for, their OPAC.  Whether you are a technical services librarian whose job it is to administer them or a reference librarian who uses them as a major research tool, it is helpful to know how discovery services work.  You need to know their features and their limitations.

The Basics

For this article, we will use Summon (with Serials Solutions) as an example.  But all discovery services share the same basic functions and features.  They consist of three major parts: the index, the link resolver, and the search interface.

Summon is a discovery service developed by ProQuest and now managed and supported by Ex Libris (since their merger).  Summon allows users to search for print and electronic resources owned or subscribed to by their library.

In my library, Summon works in conjunction with Serials Solutions 360 Link using a Summon Unified Index to provide links to ebooks (and chapters), journal articles, audio, videos, library catalog records, institutional repositories, LibGuides, and more.

Summon Unified Index
Source: http://exl-edu.com/07_Summon/Overview/Discovery/Introduction to Summon

The Summon index contains citation metadata, subject terms, abstracts, full text, and direct links (when available).  It also includes Ulrichsweb information, DOIs, altmetrics, and citation counts.

Summon Indexing

The combination of Summon and Serials Solutions employs two methods of indexing applied in this order:

  1. Summon – Index Enhanced Direct Linking (IEDL)
  2. Serials Solutions 360 Link – OpenURL Link Resolver
Summon for Researchers
Source: http://exl-edu.com/07_Summon/Overview/Discovery/Understanding the Summon Index

When you perform a search and Summon returns results, Summon first looks to see if it has a direct link to the item using its proprietary Index Enhanced Direct Linking (IEDL).  These are reliable links that point specifically to the title and are successful more than 99% of the time, according to Ex Libris.

If Summon doesn’t have an IEDL record, the metadata is passed to Serials Solutions 360 Link.  This is a link resolver that relies on OpenURL technology.  What this means is that 360 Link must build a URL containing item search metadata in a format that the database website can use.  Most broken search results links occur when either the URL is badly formed or the metadata on the database’s side is incorrect.  Fortunately, Summon gives you ways to work around the problem by providing DOIs, other database choices, or links to the ebook or journal level so that you can browse to the chapter or article.

One great feature is Summon’s ability to do a full-text search for library print book holdings by indexing electronic versions of the same title, even if they aren’t owned by your library.

Relevancy Ranking and Filters

Summon then performs relevancy ranking on the results using a proprietary method that is a combination of dynamic and static ranking. Dynamic ranking includes search term frequency, field (title, author, abstract) weighting, term manipulation (synonyms, stemming, etc.), and other functions.  Static ranking includes item attributes such as content type, date published, peer-review status, and citation counts.  Library collection items are given a higher ranking than subscription database items.

After relevancy ranking, Summon filters search results for those items that your library has access to by default.  Of course, users can see all of the relevant results by checking the “Add results beyond your library’s collection” box.

Finally, Summon offers several filters to limit results to full text, peer-review, library catalog, content type, discipline, publication date, and language.

Library Resources Management

Now that we know how Summon indexes and creates search results links, we need to know how Summon selects results that are only contained in your library’s collection.  In this sense, your “collection” means both your print holdings as well as all of the online resources you own or subscribe to.

eBook and e-Journal Holdings

In order for Summon to link to your online ebook and e-journal holdings, you must tell Summon what you own or subscribe to.  You do this by activating or “tracking” your holdings in Serials Solutions 360 Core, the back-end of 360 Link and interface for the ProQuest Knowledgebase.  You can track entire databases, publisher collections, journal titles (with specific date ranges), and individual ebooks.

Serials Solutions e-Catalog List

For each database you subscribe to, you might subscribe to all of the titles (if offered as a complete package) or you might subscribe to only some of the titles (if purchased individually).

If titles within a database are purchased individually, you must track those individual titles.  In addition, you also might need to set custom dates if you don’t subscribe to the entire run of the journal title.  If you subscribe to an entire database, new titles get added automatically when they become available.  Ebook Central can also be set up to add your newly purchased ebook titles (perpetual and DDA) automatically.  Otherwise, library staff must add new ebook and e-journal titles manually.

Serials Solutions e-Catalog Titles

Because libraries often have unique access requirements, Serials Solutions gives you a way to customize your access URL and other details.  For databases which do not have article- or ebook-level linking, you can choose to link at the database level instead.  You can choose to include your proxy URL for subscribed titles or omit it for open access resources. You can include custom journal subscription date ranges.  Finally, you can add custom public notes (such as login information).

Serials Solutions e-Catalog Details

Library Catalogs and Institutional Repositories

Discovery services can include records from your library catalog and institutional repository.  There are several different methods for getting the local records into the Summon index.

At my library, to get our library catalog indexed, we export bibliographic and holdings records from our ILS on a periodic basis and upload them via FTP to Ex Libris.  Staff at Ex Libris then add them to the Summon index (a process that can take several weeks).

For many institutional repositories, you provided Summon with access to your institutional repository metadata using Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).  Institutional repository content is then harvested automatically on a periodic basis (weekly for Summon).

Resources

Here are some great online resources to learn about discovery services:

Articles and books about discovery services:

The Future of Library Resource Discovery by Marshall Breeding

The Future of Library Resource Discovery“A white paper commissioned by the NISO Discovery to Delivery (D2D) Topic Committee” gives an overview of the current state of library discovery services and looks into how they might adapt to the future.  Published in 2015.

Access the full-text article (PDF).

E-Discovery Tools and Applications in Modern Libraries edited by Egbert de Smet and Sangeeta Dhamdhere

 My library My History Books on Google Play E-Discovery Tools and Applications in Modern LibrariesPart of the “Advances in Library and Information Science” (ALIS) series.  This book is a collection of papers covering discovery UX, e-metrics, open source, digital libraries, and library usage studies. Published in 2016.

View details and find a place to buy or borrow at Google Books.

Implementing Web-Scale Discovery Services: A Practical Guide for Librarians by JoLinda Thompson

Implementing Web-Scale Discovery Services: A Practical Guide for LibrariansNo. 9 in the “Practical Guides for Librarians” series.  From the publisher: this book is a “one-stop source for librarians seeking to evaluate, purchase, and implement a web-scale discovery service.”  Published in 2014.

View details and find a place to buy or borrow at Google Books.

Web Scale Discovery Services by Jason Vaughan

Web Scale Discovery ServicesThis title is actually an issue of Library Technology Reports from ALA Tech Source.  The report covers the content, interface, and functionality of discovery services from the major vendors to help with evaluation.  Possibly a bit dated now. Published in 2011.

View details and find a place to buy or borrow at Google Books.

6 Chrome Browser Extensions Every Librarian Needs

Google ChromeA look at global browser market share data will show that Google’s Chrome browser commands more than half of the browser market (58.4% for January 2017, to be specific).  The market share might be even higher among librarians (who have a choice at work).  If you’re not a Google Chrome user, these six browser extensions might make you switch.

If you’ve never considered browser extensions, they are plugins or small applications that add functionality to your browser.  Sometimes they work in the background (like Grammarly, below) but usually they work when you click on a small icon that gets added to the browser’s toolbar.

Chrome browser extension icons

Google has a huge Chrome Web Store for browser extensions, most of them are free.  They offer help to install and manage extensions but for the most part, a single click will install an extension.  Sometimes additional configuration options are available.

Here are six Chrome browser extensions every librarian needs.

Continue reading “6 Chrome Browser Extensions Every Librarian Needs”

OAI-PMH: Basics and Resources

Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is a set of specifications for making structured open repository metadata accessible to other service providers issuing requests.

Why learn about OAI-PMH?

Taking advantage of repositories (data providers) and services (service providers) that offer metadata using OAI-PMH will allow your resources better visibility and access.  For example, many discovery services (the “harvester”) use OAI-PMH metadata for indexing open access institutional repository articles.

The Basics

Open Archives InitiativeOpen Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) specifies how metadata is structured and presented for ingestion by external services, usually on the Internet.  OAI-PMH metadata is encoded in extensible markup language (XML) format.  OAI-PMH records are harvested using HTTP requests.

OAI-PMH is a project of the Open Archives Initiative.

Continue reading “OAI-PMH: Basics and Resources”