Difference between revisions of "What's new in 4.5"
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* New '''ns_pools''' command to map method/URL's to specific thread pools. | * New '''ns_pools''' command to map method/URL's to specific thread pools. | ||
* New '''ns_limits''' command control the number of threads executing and/or waiting for execution by method/URL. | * New '''ns_limits''' command control the number of threads executing and/or waiting for execution by method/URL. | ||
− | *'''Note:''' The new scheme does not pick up connection thread pool configurations from earlier versions of AOLServer. Please see the new example configuration files, and the documentation for [[ns_pools]] and [[ns_limits]], for instructions in upgrading your configuration. There are known issues when using this feature in conjunction with virtual servers; see the SourceForge bug list (and development mailing list archive) for details. | + | *'''Note:''' The new scheme does not pick up connection thread pool configurations from earlier versions of AOLServer. Please see the new example configuration files, and the documentation for [[ns_pools]] and [[ns_limits]], for instructions in upgrading your configuration. |
+ | ** As of 1 August 2007, the HEAD revision contains "pools.tcl", which will handle many pre-4.5 configurations. | ||
+ | ** There are known issues when using this feature in conjunction with virtual servers; see the SourceForge bug list (and development mailing list archive) for details. | ||
=== I/O Features: === | === I/O Features: === |
Revision as of 20:34, 2 August 2007
This is a partial list of new features and major changes in AOLserver 4.5 (compared to 4.0). If you know of anything that is missing, please add it.
Connection Management:
These two commands can be used together to map slow running requests to a specific pool and to set limits to avoid overload.
- New ns_pools command to map method/URL's to specific thread pools.
- New ns_limits command control the number of threads executing and/or waiting for execution by method/URL.
- Note: The new scheme does not pick up connection thread pool configurations from earlier versions of AOLServer. Please see the new example configuration files, and the documentation for ns_pools and ns_limits, for instructions in upgrading your configuration.
- As of 1 August 2007, the HEAD revision contains "pools.tcl", which will handle many pre-4.5 configurations.
- There are known issues when using this feature in conjunction with virtual servers; see the SourceForge bug list (and development mailing list archive) for details.
I/O Features:
- New Ns_QueueWait API to enable event-driven callbacks in the driver thread before dispatching to pools for processing.
- The allows drivers to augment data received from the client (headers, request, content) with additional data fetched over the network (likely stored in the new Ns_Cls "connection local storage" API's) before dispatching to the connection threads. An example would be to add certain personalization data received via a web service. The rationale here is that I/O events are cheap so do those upfront instead of having expensive connection threads burdened with wasteful blocking I/O. This is a somewhat obscure and technical interface.
- Added ability to manage larger file uploads by spooling to a temporary file.
ADP Improvements:
- Added a new execution caching technique at the ns_adp_include level which allows you to save the results of execution of an included ADP and includes below that for reuse on subsequent connections up to a specified time.
- Added singlescript config option which turns ADP pages into a single script enabling syntax such as "<% foreach e $list { %> element <%= $e %> here <% } %>".
- Added output buffer improvements via new Ns_ConnFlush.
- Added automatic UTF-8 to output charset encoding.
- Added gzip output compression.
- Added streaming output in chunked-encoding format instead of the previous "response with no length" HTTP/1.0 method.
- Enhanced ADP error handling and reporting.
- Added ability to trace ADP pages. Trace output is written to the server log.
Other Improvements:
- New Ns_TclRegisterTrace API to enable callbacks at key state transition points in a much more natural way. The ns_ictl command has been updated to support script-level traces.
- New Ns_Task API designed to replace the old Ns_SockCallback API which didn't do a very good job at managing timeouts along with I/O events.
- New ns_returnmoved command to return 301 http status code and redirect to a new URL.
- New ns_cache command based on ideas from the ns_cache module. This is not backward compatible with the ns_cache module.
- New ns_loop_ctl command to monitor and manage for, while, and foreach loops.
- Added ns_ictl package subcommand to ns_ictl command to handle loading of Tcl packages.
- Added new ns_register_fastpath command to re-enable fastpath after a previous call to ns_register_proc.
- Added ability to access more AOLserver functionality from a tclsh (nsv_*, ns_thread, etc).
- Stack checking has returned. In a multi-threaded application like AOLserver, stack checking is important for detecting buffer overruns and deep call trees blowing your thread stack, etc.
- More detailed information when logging uncaught Tcl errors. Especially for connection threads, details of the HTTP request are logged to make diagnosing the root cause of errors easier.