The user is working with an ETL Solution's CDC Staging Area, and getting the following:

Changes are not captured in the Staging Area.
The SA log file contains the following error message:

[D000] Cannot open file ...
ISAM error 110: End of file; (OPEN)
fs_util_open_entry::db_open() failed with code=-1
[N003] There was internal error in the repository returning -1 from db_open_entry

The problem is that the OPERATING SYSTEM does not support the requested amount of OPEN FILES. On some Unixes the maximum open files is 50.

The ETL (DISAM) Staging Area requires two OPEN FILES for each captured table (DAT/IDX files). The default maxOpenFiles parameter of the Router is set to '200', which may be problematic for some operating systems.

When encountering such a problem, perform the follow steps:

Check the maximum OPEN FILES capacity of the operating system. If it can be modified you can solve the problem.
If you have to work with the maximum available, use the following formula:
maxOpenFiles = ([Max Limit] - 10 /* For other uses */) / 2

So simply, decrease 10 from the maximum allowed for the operation system; so there are enough handles for the Staging Area miscellaneous work and divide it by 2, because in ETL (DISAM) we need two handles for each table.
In this example the recommendation would be to set the maxOpenFiles to 20.