Summary
Error
Note the following errors can be reproduced with ArcMC when adding TH.
They typically show up AFTER the dialog showing the cert is trusted which is misleading.
Also note the certificate of the ArcMC changes anytime you click "generate certificate" from the Administration -> System Admin -> SSL Server Certificate page.
Generating a new certificate is a required step.
Even if you have not changed any fields in the certificate settings on the ArcMC, you have to click generate certificate which will change the creation and expiration timestamps and the entire certificate signature.
Some customers do not want to generate a new certificate if they are managing that ArcMC from another, but it still is a required step to add TH or else the process can fail.
Also note the process of adding TH to ArcMC involves copying certificates to each one manually. At this time, the importing of the certificates is not automated.
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POSSIBLE ERRORS YOU MAY ENCOUNTER:
1) 403 : Forbidden
Example: Error Failed to add Cluster th1.something.net.
Error: Unexpected response body from web service. 403 : Forbidden
CAUSE:
When not using proper credentials on the ArcMC side or mistyping the password while attempting to add TH as a managed host.
2) Certificate copy failed
Example: Error Certificate copy failed.
Error: 500 Internal Server Error The call failed on the server; see server log for details
CAUSE:
If the certificate was not copied exactly from one host to the other possibly missing a single character or formatting was changed by accident, etc.
Some people will generate a certificate on the ArcMC and copy it to TH then at some future point in time click generate again which changes the certificate.
3) NullPointerException when adding by Fully Qualified Domain Name (FQDN)
Example: Error Failed to add host th1.something.net.
Error: Error while adding Transformation Hub: java.lang.NullPointerException
CAUSE:
Certificate FQDN of ArcMC is incorrect. Generate the proper certificate on the ArcMC using a fully qualified domain name.
OR
TH configuration does not have proper ArcMC cert
OR
The management port information is NOT filled in on the TH side and saved.
Even if using standard port 443 it is best to enter the FQDN of the ArcMC under the TH configuration URL
Example: arcmc.something.net:443
From the TH reconfiguration page such as this example: https://th1.something.net/suiteConfig/arcsight-installer/reconfiguration.html
Within the section "Management Center Configuration"
Under the field "Management Center host names and ports managing this cluster"
4) NullPointerException when adding by IP address
Example: Error Failed to add host 10.10.10.10.
Error: Error while adding Transformation Hub:java.lang.NullPointerException
CAUSE:
Adding by VIP or IP and not using FQDN. Try adding by FQDN.
5) Error REST Authentication Error
Example: Error REST Authentication Error
CAUSE:
Make sure using FQDN and not IP, typically seen on TH 3.0 or 3.1, but not seen after these versions as of writing of this article.
6) Error in sending http request
Example: Error Failed to add host th1.something.net.
Error: Error while adding Transformation Hub: Error in sending http request
CAUSE:
Arcmc certificate for localhost or services has issues.
Make sure arcmc dashboard shows it green before proceeding.
Resolve the certificate issue on the ArcMC side then generate and add the new certificate to the TH reconfigure side.
FURTHER SUGGESTIONS:
When ArcMC had managed a TH prior and now is being re-added or a different one to be managed, it is best to restart the entire ArcMC after deleting pre-existing TH.
If encountering errors when adding TH, it is best to clear browser cache and restart browser before trying again.
Cause
The main cause for any of these errors is either not following the directions exactly and verifying certificates are copied properly or attempting to add TH when there is a different pre-existing error on either TH or ArcMC.
Fix
The workarounds can vary. See the specific error encountered for each fix.