Skip to main content

Search

Knowledge Center

Hydrant Sync: GIS Layer Configuration Requirements

Overview

This article clarifies the technical requirements for Hydrant Sync to work reliably with your GIS provider and explains the most common reasons a sync produces unexpected results, including errors or zero hydrants synced.

Audience: All clients using Hydrant Sync with an ArcGIS-based GIS provider
Topic: Endpoint types, layer capabilities, and common causes of sync failures

Feature Service Is Not Required

Previous guidance stated that Hydrant Sync required a Feature Service endpoint. This is no longer accurate.

Hydrant Sync works with either a Feature Service or a Map Server endpoint, provided the layer meets one condition:

  • The Query capability must be enabled on the layer.

This capability, not the endpoint type, is what actually determines whether Hydrant Sync can retrieve hydrant data.

Clients using a Map Server endpoint are not using an unsupported workaround. This is a fully valid configuration as long as Query is enabled.

Action for clients: If you're setting up or troubleshooting a GIS connection, confirm with your GIS provider or administrator that the Query capability is turned on for the hydrant layer, regardless of whether it's published as a Feature Service or Map Server.

Common Issue: Errors Generating a Token

Some clients see an error when the system attempts to generate an access token during sync.

Why This Happens

The system only attempts to generate a token when a layer is marked private. When it does, it looks up your organization's saved connection configuration, including the domain and credentials, to authenticate.

What Causes the Error

If the system cannot find an active, matching connection configuration for your organization, it does not always fail visibly.

In some cases, it can fall back to a generic default configuration, which will not match your GIS environment and will result in a token/authentication error.

What to Check

If you're seeing a token generation error:

  • Confirm whether your hydrant layer is set to private or public with your GIS provider.
  • If private, verify with your FirstDue contact that an active connection configuration (domain + credentials) is on file and current for your organization.
  • If your organization's GIS domain or credentials have changed recently, this is a likely trigger. Update your connection configuration.

Common Issue: Zero Hydrants Sync With No Error Message

This is one of the more confusing symptoms because the sync appears to "succeed" but returns no data, with nothing in the logs pointing to a cause.

There are two known, confirmed causes that produce exactly this result.

Missing Location Data (Latitude/Longitude)

If a hydrant record in your GIS layer is missing its geographic coordinates, that record is silently skipped during sync.

It does not generate an error. It simply doesn't come across.

Action for clients: Have your GIS administrator confirm that every hydrant feature in the layer has valid latitude/longitude values populated.

Records missing this data will need to be corrected at the source before they'll sync.

Duplicate Unique Identifiers

Each hydrant layer is configured with a mapped unique identifier field. This is the field your organization has designated to uniquely identify each hydrant record.

The field may be called something different depending on how your layer is set up, such as:

  • ID
  • Tag number
  • Asset number

If two hydrant records share the same value in this field, the second record silently overwrites the first during sync.

No error is thrown, but the result is fewer hydrants than expected.

Action for clients: Have your GIS administrator run a check for duplicate values in the field mapped as your unique identifier.

Any duplicates should be corrected so each hydrant has a distinct value.

Note on terminology: You may see references to a "facility ID" or "hydrant ID" field in older documentation or support conversations. There is no field literally named this in the system. What matters is whichever field is configured as the unique identifier for your layer. The same rules above — no nulls and no duplicates — apply to that field regardless of its name.

Quick Reference Checklist

Use this checklist when setting up a new Hydrant Sync connection or troubleshooting an existing one:

  • Layer is published as either a Feature Service or Map Server.
  • Query capability is enabled on the hydrant layer.
  • If the layer is private, an active connection configuration (domain + credentials) is on file and current.
  • Every hydrant record has valid latitude/longitude values.
  • The field mapped as the unique identifier contains no null or duplicate values.

Additional Support

If you've confirmed all of the above and are still experiencing sync issues, contact FirstDue Support with your organization name and GIS layer URL so we can investigate further.