This document discusses the problems related to the DLLHOST process,
used for all COM+ applications, and possible solutions to resolve issues with
this host process.
There are no specific requirements for this document.
The information in this document is based on these software and
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
The DLLHOST process is used on all versions of Windows 2000 and is the
host process for all COM+ applications. Window's systems use COM+ to manage and
execute ASP pages (Internet Information Server (IIS)/services). Therefore, when
you call an ASP page, the DLLHOST is used to execute the ASP page.
Specifically, the DLLHOST is the host process for all COM+
applications. Distributed Component Object Model (DCOM) is the support module
for Dynamic Link Library (DLL) based COM objects. DCOM is a software
architecture model that is an intrinsic part of Windows, of most Microsoft
products, and of many non-Microsoft products that take advantage of COM+ or
DCOM. In most cases, you should never see DLLHOST in your Task List. Typically
DLLHOST starts and perform its function and then terminates. However,
sometimes, if a Java COM object runs (this could happen if you browse the
and come to a page which has Java code), DLLHOST
might not terminate, which is when you would see it in your Task List.
It is important not to perform an End Task, as there is no way to
determine whether DLLHOST has completed its task or not. More advanced users
can delete the registry key "HKEY_LOCAL_MACHINE\SOFTWARE\ Microsoft\Java VM\
MSDebug", which can solve the problem where DLLHOST constantly appears in the
Task List. The DLLHOST is usually stable but occasionally the DLL it manages
might cause problems. The Solution section of
this document shows how to identify a memory leak within the DLLHOST
For more information, refer to the
(registered customers only)
for the latest Windows Operating System
(OS) and Structured Query Language (SQL) information.
The first task is to identify which COM+ application leaks in the
DLLHOST process. These steps provide a basis to begin to troubleshoot this
Within Task Manager, identify the process identifier (PID)
associated with the DLLHOST.EXE file.
Select Start > Programs >
Administrative Tools >Component Services.
Expand Component Services >
Computers > My Computer > COM+
Highlight COM+ Applications.
Right click COM+ and select View
> Status View.
In the right-hand pane, the associated PID is listed to the right
of each active COM+ application. Use these PIDs as a direct cross-reference to
the PID identified within Task Manager.
In this example, Task Manager's DLLHOST references PID 2456, which
is accessing over 200 mb of memory. In Component Services, PID 2456 is
associated with "IIS Out-Of Process Pooled Applications". In this case, Cisco
CallManager hits Cisco bug ID
(registered customers only)
, which relates to Multilevel
Administration Access (MLA) that uses the "IIS Out-Of Process Pooled
Application" to leak memory. In this situation, using the CCMAdministrator
account instead of the MLA account will solve the issue.
With this information you can go to both the
web site and
Cisco.com, and search for the COM+
applications to see if a known bug is the issue.
Alternatively, you can verify the amount of private bytes of
DLLHOST with perfmon. If the number of private bytes remain constant for a
number of days, there is no memory leak. If you see the number of private bytes
increase, there is a memory leak that needs to be identified.
Before you decide to open a service request with Cisco Technical
Support on these issues, gather this information and have it available for your
technical support engineer:
Gather any Event Logs which might relate to the
Gather Windows SQL patches. In order to do this, select
Start > Programs > Microsoft
SQL Server 7.0 <Version> > Query
Enter select @@version and perform the query (top
middle green arrow).
Gather any Windows patches. In order to do this, select
Start > Run, and enter