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Change a remote server connection

Important distinction​

A DCP server record stores the address and SSH connection details. Removing that record does not uninstall DerScanner from the server. DCP 1.0.17 has no separate edit form for a saved connection; replace the connection record to change its details.

Before you begin​

Record the name, address, port, user, product directory and verified SSH fingerprint. Prepare the new key or password. Ensure no DCP operation is active on the node. If the record is used by a scanner node or Builder, document those associations first: a replacement record receives a different internal identifier. Treat replacement as maintenance that can interrupt the node: removal can close the DCP-managed rule allowing that node to reach the Core queue on port 61616. Re-adding the record alone does not guarantee that connectivity is restored.

Procedure​

  1. Open Servers and identify the record by name and address.
  2. If it is selected, switch to This server to avoid acting in the wrong context.
  3. Verify the selected record before clicking Remove this server: the panel asks "Remove … from the list?" and explains that it forgets the sign-in and the trusted key of that server and does not change DerScanner there. For a scanner node of this Core you also type its name: once removed, the node gets no more tasks from this server. Do not remove a module to change an SSH password.
  4. Click Add a remote server.
  5. Enter the name, address, SSH port, user and product directory. Use the actual existing installation directory.
  6. Select key or password authentication. Use the key field or file chooser for a private key; do not put it in the server description.
  7. Save the record and proceed to host-key confirmation.
  8. Compare the displayed fingerprint with the value obtained from the server administrator; the administrator of that server can compare it with the output of ssh-keygen -l -f <file> there (the panel names the file). A changed address is not sufficient reason to trust an unexpected key.
  9. Confirm the correct key, run the server check and verify that DCP recognises the existing installation.
  10. For a scanner node, restore authorised queue access on the main server if DCP managed it: the Core administrator runs sudo dcp firewall open-queue --node <node-address> --yes. Substitute the actual node address, rather than opening the port to arbitrary networks. Check node connectivity to Core:61616 and execute a job.
  11. For Builder, a replacement server entry does not automatically transfer the existing Builder association to its new identifier. Arrange the association change with support before deleting its original entry; use Replace a server or relocate a component for deliberate Builder replacement. Do not start a fresh installation over the existing Builder. End maintenance only after checking the connection and a functional build.

Troubleshooting​

Check the SSH port, username, key permissions and administrative privileges. For a fingerprint mismatch, establish whether the server was rebuilt. If the host appears empty, check the product directory first.

SSH requirements​

The DCP form accepts a private key without a passphrase. A non-root account requires sudo -n, with no interactive password prompt. An SSH password is not supplied as a sudo password. Use a dedicated administrative account and protected key storage.