About Z-alarm

About Z-alarm

Z-alarm is a network service to assist the managers of information servers to ensure that their facilities are reliably available.

Our robot conducts a suite of individual tests against each Z59.50 target, producing detailed reports and summaries. The tests focus on conformance to the "Z39.50 Application Profile for Geospatial Metadata (GEO)" version 2.2

These tests identify potential mis-configurations of each target by starting with simple queries and progressively building more complex queries based on the results of the previous tests.

Our Z-alarm client waits for an appropriate amount of time between each query, so as to be kind to the target servers. Load testing is not conducted.

The "full reports" for each target are protected so that only the relevant people can see them. Please contact IndexGeo to gain access or to get a new target configured. For a small fee, we will provide access to your full report and also provide some commentary and assist you to rectify your configuration issues.

Start at the Z-alarm home page and review the "Compliance tables" and "Sample full report".

The need for monitoring

Each node that participates in a spatial data directory, needs to be properly configured to respond to all potential queries. Otherwise people who search these directories will receive failures or spurious results. Also the data directory cannot be relied upon to provide an infrastructure for other geographic information services.

Reasons for failures

The test searches will be recorded as failures if the appropriate response is not received from their server. This is normally due to configuration errors at their end, for example if their server configuration file was missing a mapping for Use Attribute 1012 (metadata date) then date searches would fail.

Poor quality metadata can also manifest as configuration errors. For example, if all of their dataset descriptions were missing the mandatory "metadata date (metd)" field, then searches against that Use Attribute would fail. Similarly, content errors would cause problems, e.g. dates in the wrong format, spatial co-ordinates out-of-range.

Reasons for failures are usually obvious and listed on your full report. If not, then contact us to discuss it.

Target selection

Only a selection of the available targets are currently monitored. We have specifically chosen some targets. Others can be added on request.

The public connection details are gathered from the lists at ASDD and GSDI Registry.

About Z39.50

Z39.50 (ISO 23950) is the information search and retrieve protocol. The main references are: Z39.50 Maintenance Agency and the GEO Profile and the ASDD Tech pages.

HTTP-Z39.50 search gateways

One way to search a set of Z39.50 information servers is to use your web browser via a "gateway" that translates between the HTTP protocol of the WWW and the Z39.50 protocol. See various Australasian gateways