Coping with DTC issues

Software

Windows Server 2003 SP1
DTC (Distributed Transaction Coordinator)

Issue

Whenever you get an error in Event Log about some transaction issue the reason may be in broken DTC (Distributed Transaction Coordinator) communication between your servers.

Solution

Here are some tips on how to cope with DTC-related issues that I collected while working on my projects:

- Use Microsoft's dtcping.exe utility to check if communication is ok between the servers
- Windows Server 2003 should have SP1
- In Component services, right-click My Computer, Properties, on MSDTC tab, in Security settings: Enable Inbound, Outbound; No athentication. This might not be good for prod scenario, but is ok to diagnose the problem.
- if machines are virtual PCs and were cloned from a common parent, then do the following on both servers:
msdtc -uninstall
msdtc -install
- make sure port 135 is open bi-directionally (use telnet or nmap)
- if there's internal network make sure host names are resolved as internal IPs; external IPs may have a firewall between them that prevents communications
- Make sure Distributed Transaction Coordinator service is started on both machines
- Restart the machines

UPDATE (on 7 March 2014)

- This registry fix may be required for the dtcping utility to work:

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\RPC]
"RestrictRemoteClients"=dword:00000000
"EnableAuthEpresolution"=dword:00000000

- One more thing that seems to have fixed DTC communication in my case was that I added servers to WINS configuration in IPv4 properties. The server IPs I entered were taken from similar configuration on a machine which was known to have been properly configured for DTC communication.

- Also. Select option "Enable NetBIOS over TCP/IP" in WINS configuration screen in IPv4 properties.

dcomcnfg.exe

Мдя... Что я говорил? Паразитизм.

Не говори, понаставили всяких галочек, кнопочек, окошечек. Зачастую полдня потратишь прежде чем нужную галку где-нить в недрах Виндов найдёшь. Можно было всё в сто раз проще и понятнее делать.

Добавил в пост про DTC ещё пару моментов. Хочется сказать, что это удивительно, что пост восьмилетней давности всё ещё актуален. DTC очень живуч.