iTP Active Transaction Pages (iTP ATP) Programmer's Guide

Installing and Running ATP
iTP Active Transaction Pages (iTP ATP) Programmer’s Guide—522292-002
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ATP Environment Variables
ATP_COMPILE
This variable is obsolete because ATP V20 and ATP V21 always have the cache for
compiled pages.
If you have configured a web-page cache, you can further improve performance by
having the script pseudo-code retained in the cache. In this case, ATP need not
compile the script each time that the web page is used. Compiled pseudo-code
retention can make a noticeable difference in performance.
Set the ATP_COMPILE environment variable either globally, by specifying Env
ATP_COMPILE=1 for the atp.pway server class, or locally (for a set of
directories) by specifying AddCGI ATP_COMPILE 1 in a Region command. At
the individual page level, use <meta compile="on"> anywhere before the
</head> tag. The permissible values of this variable are 0 or 1, ON or OFF.
ATP_PAGE_CACHE_SIGNAL
This variable is obsolete because the ATP V20 and ATP V21 versions of atp.pway
check the time stamp to recompile the source files on demand.
ATP_SCRIPT_STACKSIZE
Include this variable in the Env directive to specify the chunk size in which the
script interpreter stack is allocated. The default value is 32000. Increase the value
only if your application runs out of memory; the maximum value is 96 megabytes
(your system maximum memory may be lower than this value).
ATP_SCRIPT_RUNTIME_SIZE
Include this variable in the Env directive to specify the memory size of the heap
used by script interpreter. The default value is 1000000. Increase the value only if
your application runs out of memory; the maximum value is 96 megabytes (your
system maximum memory may be lower than this value).
SQL_STATEMENT_CACHE_SIZE
If you plan to use JavaScript objects for access to NonStop SQL, use this
environment variable to increase the size of the SQL statement cache. The default
value is 50 statements. The minimum value is 20.
A large SQL statement cache could cause the atp.pway process to run out of PFS
space because of the number of open SQL tables. You can use nld to increase the
amount of PFS space. A guideline for setting the SQL statement cache size is to add
some slack to the greater of
•
The maximum number of SQL statements on any one web page
•
The aggregate number of SQL statements on the most frequently used pages
Note. If you choose this option, ensure that the web page does not preserve context that
could result in errors on repeated invocation. For example, ensure that the web page
initializes its variables, closes SQL cursors, and commits or rolls back transactions as
appropriate