SYSTEM.CHANNEL.SYNCQ 中待处理的消息

Question

SYSTEM.CHANNEL.SYNCQ 上有 13 条消息待处理。这个队列中有消息是什么意思以及如何处理它们。我们可以删除那些消息吗？

dis qs(SYSTEM.CHANNEL.SYNCQ)
     6 : dis qs(SYSTEM.CHANNEL.SYNCQ)
AMQ8450: Display queue status details.
   QUEUE(SYSTEM.CHANNEL.SYNCQ)             TYPE(QUEUE)
   CURDEPTH(13)                            IPPROCS(0)
   LGETDATE(2017-09-21)                    LGETTIME(10.22.23)
   LPUTDATE(2017-09-21)                    LPUTTIME(10.22.23)
   MEDIALOG( )                             MONQ(MEDIUM)
   MSGAGE(2986548)                         OPPROCS(0)
   QTIME(15855166, 205244561)              UNCOM(NO)

Answer 1

您不应删除此 queue 中的消息。它是一个 queue 由 MQ 内部使用来保存通道的同步数据。

IBM v7.5 知识中心页面“System and default objects”：

中记录了此内容和大多数其他 SYSTEM.* queue 的目的

Table 1. System and default objects: queues
-----------------------+-------------------------------------------------------------
Object name            |  Description
-----------------------+-------------------------------------------------------------
SYSTEM.CHANNEL.SYNCQ   |  The queue that holds the synchronization data for channels.

由于 queue 由 MQ 产品在内部使用，因此没有关于此用途的其他知识中心文档。

Paul Clarke 在 2002 年向 MQSeries Listserv 提供的标题为“Re: SYSTEM.CHANNEL.SYNCQ”的 post 提供了一些额外的详细信息。请注意，Paul 在 2002 年是为 IBM 工作的 MQ 开发人员，因此该信息是可信的：

The SYSTEM.CHANNEL.SYNCQ contains essentially two types of messages, both to do with storing channel status.

1/ There is a message (possibly two) for each instance of channel that has run and transferred a persistent message to a remote partner. These messages maintain the synchronisation state between the two ends of the channels. If you delete these messages your channel will forget where it got to. This will almost certainly lead to sequence number problems since the channel will start at 1 again and you will have to issue RESET CHANNEL. In the worst case, if the channel was indoubt, you may may also cause messages to be duplicated.

2/ There may also be a message recording the status of the channel. In other words, whether the channel is STOPPED, RETRYING etc etc. If you delete these messages the worsed that will happen is that when you recycle your Queue Manager a channel will come up inactive rather than STOPPED or RETRYING.

SYSTEM.CHANNEL.SYNCQ 中待处理的消息

Messages pending in SYSTEM.CHANNEL.SYNCQ

ibm-mq