DRC INSIGHT Central Office Services (COS) Installation and Troubleshooting SOPe
Overview
This SOP provides step-by-step instructions to install, configure, validate, and troubleshoot the DRC INSIGHT Central- OfficeCOS ServicesTroubleshooting (COS)SOP
Service
Purpose: DeviceResolve onthe Linux,most withcommon deploymentLinux notesCOS forinstallation, Chromebooksservice, and portalChromebook configuration guidance.issues.
1.Issue Purpose
The COS Service Device provides local content hosting for DRC INSIGHT testing devices. This reduces internet dependency, improves consistency during testing, and allows testing content to be delivered from the local network instead of the cloud whenever COS is available.
2. DRC COS Architecture
Testing Devices
↓
DRC INSIGHT Secure App
↓
COS Service Device
↓
Local Content Hosting
↓
Fallback to DRC Cloud if COS unavailable
DRC describes the COS Service Device as a local content hosting device, and notes that testing devices can connect to any supported COS operating system type. The training deck also shows that test content is delivered from the COS Service Device when available, and from CloudFront if the COS Service Device is unavailable. :contentReference[oaicite:0]{index=0}
3. Supported Platforms
DRC's August 2025 Pennsylvania training deck states that DRC INSIGHT Secure Applications are supported on Windows, macOS, Linux, iPadOS, and ChromeOS, while COS Service Devices are supported on Windows, macOS, and Linux. :contentReference[oaicite:1]{index=1}
4. Linux Installation Procedure
4.1 Prepare the System
sudo apt update
sudo apt install -y curl unzip
sudo chmod 1777 /tmp
ls -ld /tmp
The /tmp directory must be writable. A failed COS install can occur if the installer cannot create its temporary lock file.
4.2 Clean Up a Failed Installation
sudo rm -rf /opt/CentralOffice
sudo rm -f /tmp/coinstaller*.lock
4.3 Run the Installer
chmod +x silent-linux.sh
sudo ./silent-linux.sh
DRC recommends using the default locations during installation. The training deck also states that the installation wizard will present a completion URL that should be saved because it can be used to resume the process without reinstalling the COS Service Device. :contentReference[oaicite:2]{index=2}
4.4 Default COS Service Ports
According to the DRC training deck, the installer typically uses a base port of 55222, and then automatically assigns consecutive ports. :contentReference[oaicite:3]{index=3}
In this deployment, the observed active ports were:
5. Verify COS Services
5.1 Check Registered Services
systemctl list-unit-files | grep -Ei 'central|drc|relay|proxy|content'
5.2 Check Running Node Processes
sudo /opt/CentralOffice/node \
/opt/CentralOffice/setup/node_modules/forever/bin/forever -p /opt/CentralOffice list
Expected running components:
5.3 Check Listening Ports
sudo ss -tulnp | grep node
5.4 Validate Local HTTP Response
curl -I http://127.0.0.1:55223
curl -I http://127.0.0.1:55224
curl -I http://127.0.0.1:55225
An HTTP 404 on the root path does not necessarily indicate failure. It confirms that the HTTP service is alive but may require a specific application route.
6. DRC Portal Configuration
6.1 Content Management
The training deck states that Content Management is used to select the testing content and accommodations to be hosted on the COS Service Device. It also notes that VSL must be selected each year, while TTS/HVA may remain checked from the prior year. :contentReference[oaicite:4]{index=4}
6.2 Content Hosting
6.3 Proxy Configuration
For a normal single COS Service Device deployment, avoid unnecessary proxy layering unless DRC support or site network policy requires it.
7. Device Registration
The training deck states that devices with the DRC INSIGHT Secure Application are registered to a COS Configuration, and that one way to assign testing devices is to manually assign the COS ORG Unit ID. :contentReference[oaicite:5]{index=5}
7.1 Register a Device Manually
8. Chromebook Deployment SOP
8.1 Install the App
DRC states that for ChromeOS, the installer is available through a Google Play deployment path and should be deployed using the Google Admin console. :contentReference[oaicite:6]{index=6}
8.2 Chromebook Settings Required by DRC
The Pennsylvania training deck specifically states that ChromeOS display size should be 100%, and that ChromeOS devices must use the US English keyboard so quotation marks and apostrophes display correctly. :contentReference[oaicite:7]{index=7}
8.3 Recommended Chromebook Preparation
9. Network and Firewall Requirements
9.1 Internal Network
Allow testing devices to reach the COS server on the configured service ports.
sudo ufw allow 55223/tcp
sudo ufw allow 55224/tcp
sudo ufw allow 55225/tcp
9.2 DRC Allowlist
The DRC training deck lists a shared allowlist and states that wildcard *.drcedirect.com should be allowed, with ports 80 and 443 permitted. :contentReference[oaicite:8]{index=8}
Key URLs from the deck include:
9.3 Ports
10. Validate Content Download
10.1 Check Local Content Directory
ls -lah /opt/CentralOffice/content_fs
Content should populate after the configuration is updated and the required administrations are selected.
10.2 Monitor Content Services
sudo journalctl -u centralofficecontenthosting -f
sudo journalctl -u centralofficerelay -f
11. Troubleshooting SOP
11.1 Installer Fails or Stops Early
Symptoms:
MissingNo usable COSfiles under/opt/CentralOffice- Installer exits
without completingquickly - Lock file or temp errors
in/tmp
Fix:
sudo chmod 1777 /tmp
sudo rm -rf /opt/CentralOffice
sudo rm -f /tmp/coinstaller*.lock
sudo ./silent-linux.sh
11.
Issue 2 - Only Proxy Runs
Symptoms:
forever listshows only proxyOtherrelayservicesandappear to start butcontenthosting do not stayuprunning
Likely Cause:
Fix:
11.
Issue 3 - Relay Error: Heartbeat returned undefinedError
Observed error:Error:
Error: CO API - Heartbeat returned undefined
Meaning:
The relay could start but did not receive the expected heartbeat response from the DRC Central Office API. This usually indicates incomplete registration, missing configuration, or upstream reachability issues.
Checks:Cause:
ConfirmRegistrationthe registration/setup URL was completedincompleteConfirmDRCoutboundAPIinternetnotaccessreachableConfirmUpstreamDRCfilteringallowlistoris permitted
11.
Fix:
Issue 4 - Services Show "active (exited)"
This maycan be expected.normal. COS uses forever to launch the Node services in the background, so the systemd wrapper may show the wrapper script as exited while the actualNode serviceprocesses continuescontinue underrunning.
Use foreverthis listprimarytruth runtime check.source:
11.
sudo /opt/CentralOffice/node \
/opt/CentralOffice/setup/node_modules/forever/bin/forever -p /opt/CentralOffice listIssue 5 - Chromebooks Cannot Load Tests
Connect
Checks:Check:
Confirm the DRC INSIGHT app is installed
12.Issue Operational6 Best- PracticesContent Does Not Download
Check:
Use a dedicated COS Service Device when possible
The training deck recommends reviewing background processes and temporarily disabling automatic updates and software that could interfere with testing. Examples listed include classroom monitoring tools, remote access tools, collaboration tools, screen capture software, and typing assistants. :contentReference[oaicite:9]{index=9}
13. Validation Checklist
COS Server
forever listPortal
Chromebooks
14.Useful DRC ResourcesCommands
The
# DRCCheck trainingruntime deckservices
listssudo the/opt/CentralOffice/node following\
readiness/opt/CentralOffice/setup/node_modules/forever/bin/forever and-p support/opt/CentralOffice resourceslist
in# theCheck portal:ports
The deck also references the online testing system status page:
Status URL: https://status.drcedirect.com/PA
15. Support Contacts
DRC WIDAStatus CustomerPage: Service
End of Troubleshooting SOP