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| PeterPotkay |
 Posted: Mon Dec 06, 2004 6:37 am Post subject: Limiting Connections from a Client Server |
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Poobah
Joined: 15 May 2001
Posts: 7722
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We can preach about Standards and Guidelines till we are blue in the face talking about how an app is supposed to clean up after itself, and that an app that processes 1000 messages a day does not need a pool of 25 connections, but at the end of the day we have no control on how many MQ client connections an application can attempt. In a shared environment, MQClient AppA on Server A can spawn off a thousand connections to QM1, and MQClient AppB is then shut out because max connections was hit. JMS with its connection pools has only made this worse.
Is there any way to protect from this? Its almost as if there needs to be a MaxActiveChannels stanza at the channel level. If I give every app a dedicated SVRCONN channel, and then say there can only be 25 instances of that channel I would be safe.
Or, maybe there is a network setting that says Server1 (the client) can only have x TCP connections into my QM server, and that way Server2, Server3.... can still connect.
Is there anyway to protect from inconsiderate and/or badly written client apps?
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Peter Potkay
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| PeterPotkay |
| Posted: Mon Dec 06, 2004 6:48 am Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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Scott on ths list server showed me this:
http://www-1.ibm.com/support/docview.wss?rs=203&uid=swg24004771&loc=en_U
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ME71 provides a security exit that allows client connections to be limited according to the name of the Server Connection channel.
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But what if I already have an exit on that channel for other reasons?
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Peter Potkay
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| Nigelg |
| Posted: Mon Dec 06, 2004 7:09 am Post subject: |
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Grand Master
Joined: 02 Aug 2004
Posts: 1046
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Add another exit.
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| On AIX, Compaq OpenVMS, HP-UX, Linux, OS/2 Warp, Solaris, and Windows, you can specify the name of more than one exit program by specifying multiple strings separated by commas. However, the total number of characters specified must not exceed 999. |
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| PeterPotkay |
| Posted: Mon Dec 06, 2004 7:13 am Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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Does that comment apply to Security Exits to? Because that note is only listed under Message Exits. 
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Peter Potkay
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| Nigelg |
| Posted: Mon Dec 06, 2004 7:24 am Post subject: |
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Grand Master
Joined: 02 Aug 2004
Posts: 1046
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Yes. In the description of SCYEXIT
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| The format and maximum length of the name is the same as for MSGEXIT. |
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| markt |
| Posted: Mon Dec 06, 2004 8:05 am Post subject: |
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Knight
Joined: 14 May 2002
Posts: 508
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| You can only have a single security exit on a channel. While the name/format is the same for all exit types, the list is not available for security exits. |
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| Nigelg |
| Posted: Mon Dec 06, 2004 8:20 am Post subject: |
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Grand Master
Joined: 02 Aug 2004
Posts: 1046
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| Sorry, markt is right, you can only have one security exit on a channel. I think that manual extract is rather misleading... |
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