SharePoint Enterprise Search Basic Knowledge Point Collection Series 3

Filter Deamon

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Deamon is a daemon. in the search for SharePoint 2007, the role name is mssdmn.exe, which is a process used for sacrifice and stores the cannon fodder process of protocol handler and filters. these filters all implement a standard interface IFilter. it is called a cannon fodder process because the mssdmn.exe process is deemed to have been terminated in the foreign pointsearch design. at the same time, we can have five mssdmn.exe processes. One is the main process, and the other is the auxiliary process. in the registry, you can set How much memory these daemon can consume.

 

Protocol Handler

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Protocol handler is a component that understands different types of objects to be searched. the type of the target determines the mechanism of the content to communicate with the SharePoint search, such as sts2: //, sts3: //, http: //, spsimport: //, anchorqh: //, and so on. the public folders of exchange, HTTP, WSS, and SMB all have different protocol handler.

 

Filter

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The Filter component can understand specific types of documents. The default SharePoint provides the filter for HTML and Office documents.

 

Relationship between mssearch.exeand mssdmn.exe

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Let's talk a little more here. What is the relationship between mssearch.exeand mssdmn.exe? Mssdmn.exeis originally separated from mssearch.exe, and its core is a defensive programming idea. because many different types of documents are stored on the SharePoint site, some types of documents are not understood by Microsoft products, such as PDF and rar. at this time, the user will use a third-party Filter and protocol handler to parse these types of documents. whether these filters are robust enough does not affect the Search performance that Microsoft cannot predict. therefore, remove the filterset to the mssdmn.exe process. in this way, even if the filter process crashes, the entire search service will not be greatly affected.

 

Mssdmn.exeand mssearch.exe communicate with each other through shared memory (shared memory). when processing a document, the filter daemonsends the chunksent to the mssearch.exe process.

 

There is a Gatherer Project in the mssearch.exe process. the Gatherer Project is considered as the entry for chunk processing. in the Gatherer Project, the chunk will be provided to a variety of plug-in, which will process the chunk provided to it.

 

There is a thread pool in the mssearch.exe process, and a filtering thread is used to handle each chunk. any type of document can be processed by any filtering thread at this level, because at this step, the document type difference does not exist.