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Minutes of meeting 15/11/00 @ 11am |
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Locate UKC Computer Science Meeting Room |
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Location: UKC Computer Science Meeting Room |
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Present: ab11, ajm4, pjm2, tdb1 |
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Absent: None |
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Meeting postponed until firealarm finishes. It is noted |
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that Ash and Paul would have been burnt alive if there |
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was a real fire. |
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Meeting postponed until firealarm finishes. It is noted that |
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Ash and Paul would have been burnt alive if there was a real |
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fire. |
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Meeting re-started at 11:20am. |
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Discussed the XML packet life problem. This has been |
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identified as a problem because corba passes references |
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to objects making it hard to determine when the object |
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should be distroyed. |
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Discussed the XML packet life problem. This has been |
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identified as a problem because corba passes references to |
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objects making it hard to determine when the object should |
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be distroyed. |
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Paul begins implementation of a quotes page. |
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Paul suggests that packets should be stored in a queue |
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structure, with 2 integers indicating how far through |
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the queue each accessing function has got (from the start |
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of the queue). This should be more efficicent than |
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storing flags inside each of the XML packet objects. |
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structure, with 2 integers indicating how far through the |
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queue each accessing function has got (from the start of the |
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queue). This should be more efficient than storing flags |
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inside each of the XML packet objects. |
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Someone needs to find out if you can 'clone' an object |
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over corba. This would solve a lot of local copy problems. |
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Someone needs to find out if you can 'clone' an object over |
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corba. This would solve a lot of local copy problems. This |
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thought was rejected by iau in the meeting. |
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Discussion of whether UDP packets should be numbered or |
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timestamped proved controversal. In the end it was decided |
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important that the host's time is setup accurately by the |
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sysadmin. |
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Meeting concluded @ 12:40 |
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The whole issue of packet content is more of a host & client |
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design issue than a server issue. |
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It was mentioned that the logging system should be able to |
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deal with verbosity levels, in a similar way to JacORB. This |
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would allow trivial messages to be hidden most of the time. |
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The possibility of multiple loggers might also want to be |
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consider (eg. file log with high verbosity, and screen log |
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with low verbosity, running in parallel). |
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Meeting concluded @ 12:40 |
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Meeting continued @ 12:45 by a tree |
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Present: ajm4, pjm2, tdb1 |
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Discussion continued about the design of the filter system. |
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The whole issue of how and where packets will be stored |
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within the system needed clearing up before implementation |
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could continue. |
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It was noted that the key function of the filter (given it's |
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called a "filter") is to remove any packets of data it sees |
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fit. With this in mind it was decided that the data could be |
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passed on in text (or rather XML) format through the child |
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filters. |
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This would work as follows in a child filter. Data would be |
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recieved by one of two means, UDP or CORBA. The hosts would |
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be sending UDP to the filter, and other "up-stream" child |
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filters would send over CORBA. Regardless, it will always be |
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the same content - a String of XML. In essence this means |
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that the filter will be sending and receiving exactly the |
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same string of XML - without any conversion required. |
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Internally it may be verified through "plug-ins" to see if |
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it should be dropped, but this would just be a series of |
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independant tests. Finally the string will be passed on if |
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the plug-ins allow. |
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This allows a chain of child filters going on and on in a |
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tree-like fashion, which is what our original design |
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permitted. |
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Finally, the parent filter will recieve all the data from |
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the child filters, and turn them into XMLPackets. These |
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packets will be stored in some kind of data structure to be |
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accessed by the various parts of the system. |
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This solves many of our key problems. |
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Meeting concluded @ 13:25 |
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Meeting continued @ 13:40 with iau |
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iau briefly suggested that we alter the location of the |
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database in our system. He suggested moving this into the |
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parent filter, and then having the data passed straight on |
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to the client interface. |
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Nothing firm was decided, but it should be analysed further. |
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Meeting concluded @ 13:55 |
