Map file change under load - possible corruption

[alextar Profile]

We are using ISAPI 3.1.0.82 and following rule with sitemapper.txt file. This file is dynamically updated by software. We had an issue, when lookup in a sitemapper.txt file has stopped finding records right after file was updated. On next update of sitemapper.txt (without IIS restart) lookup returned to normal.
Is there a known issue, race condition, which can explain this behavior?

Will upgrade to latest version will help?


RewriteMap sitemap txt:sitemapper.txt [NC]
RewriteCond %{HTTP:Host} ^([^.]+)\.outsite\.com$
RewriteRule ^/([^/]+)/(.*)$ /$1/${sitemap:%1|notfound}/$2 [QSA]

[Yaroslav]

Hello.

Watching for changes in map files was never supposed to be a future, sorry. If you need to reload file in real time you may simply write an .htaccess file that contains RewriteMap directive every time you change map file automatically. It is possible to write .htaccess file without changing anything in it and it will still trigger reload.

[alextar Profile]

This is important information, thanks for update. So file is not watched and change is not supposed to be picked up.
Is this file cached in memory or read from disk on every request? Is it possible that file change under the load has caused corruption or failed lookups?