On Tue, Mar 4, 2014 at 4:01 PM, isaac hazan <[email protected]>wrote:
> Thx. > > Is a segment a single file with multiple documents? Or is it multiple > files that together form a segment? In other terms I don't fully understand > why the notion of segment exists? > The simple answer is that a segment is made of several files. Typically, there is one that is used to store "stored fields" (allowing to get the original field values given a document ID), one for the terms dictionary (the unique terms in your documents), one for postings lists (which given a term can return the list of documents that contain this term), one for deleted documents, etc. And an index is the union of several segments. Searching an index is effectively searching every segment and merging results together. But for your information, there is an optimization called "compound file" which allows to store all these logical files of one segment in a single physical file when the segment is small. This helps save file descriptors. > Does the fact that I have a high number in the throttling KPI mean that > I have a problem in performance and if so is there a setting to tune it > properly? > A high throttling time is not necessarily an issue, it just means that merges have been occasionally paused so that search remains fast. You can disable merge throttling if you want by setting index.store.throttle.max_bytes_per_sec[1] to -1. [1] http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/index-modules-store.html#store-throttling -- Adrien Grand -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAL6Z4j7ww%3Dw8f_b-HyPiMPnc5QZwcb6%3DGFPJzD46o%2BePnOa_4A%40mail.gmail.com. For more options, visit https://groups.google.com/groups/opt_out.
