Correct. For a specific fragment, the size is adjusted to be approximately the size of the content in the fragment. When we talk of "fragment size" we generally mean the maximum allowed size.
On Thursday, June 1, 2017, 8:39:00 PM CDT, Anh Le Duc (2) <anh...@vng.com.vn> wrote: @Alan: Fragment sizes are not fixed, right? By the formula in section Stripe Directory <https://docs.trafficserver.apache.org/en/latest/developer-guide/cache-architecture/architecture.en.html#stripe-directory>, we have adaptive sizes ( *size* + 1 ) * 2 ^ ( CACHE_BLOCK_SHIFT + 3 * *big* ) On Fri, Jun 2, 2017 at 2:05 AM, John Plevyak <jplev...@acm.org> wrote: > While large objects are not stored contiguously, the chunk size is > configurable (as Alan pointed out). > Increasing the chunk size increases memory usage and decreases the number > of seeks required to > read an object. It does not decease the number of seeks required to write > the object because > we use a write buffer which is separately sized for write aggregation. > > The default chunk size is set such that for spinning media (HDDs) the > amount of time spent reading > the object is dominated by transfer time, meaning that total disk time will > decrease by only > a small amount if the chunk size is increased. Indeed for SSDs, the chunk > size can be > decreased to free up more memory for the RAM cache and to decrease the > number of > different block sizes. > > On Thu, Jun 1, 2017 at 5:46 AM, Alan Carroll < > solidwallofc...@yahoo-inc.com.invalid> wrote: > > > You might try playing with the expected fragment size. That's tunable and > > you can get a partial effect of more contiguous fragments by making it > > larger, although I think the absolute maximum is 16M. This doesn't cost > > additional disk space as it is a maximum fragment size, not a forced one. > > > > > -- *Anh Le (Mr.)* *Senior Software Engineer* *Zalo Technical Dept., Zalo Group, **VNG Corporation* 5th floor, D29 Building, Pham Van Bach Street, Hanoi, Vietnam *M:* (+84) 987 816 461 *E:* anh...@vng.com.vn *W: *www.vng.com.vn <http://www.google.com/url?q=http%3A%2F%2Fwww.vng.com.vn&sa=D&sntz=1&usg=AFQjCNHYo7I_1mPESzfIvCNjLtAJOq8xsg> *“Make the Internet change Vietnamese lives”*
