Queens Series Release Notes¶
0.23.0¶
Prelude¶
This was a quiet development cycle for the glance_store library. One new feature was added to the Swift store driver. Several bugs were fixed and some code changes were committed to increase stability.
New Features¶
A BufferedReader has been added to the Swift store driver in order to enable better recovery from errors during uploads of large image files. Because this reader buffers image data, it could cause Glance to use a much larger amount of disk space, and so the Buffered Reader is not enabled by default.
To use the new reader with the Swift store, you must do the following:
Set the
glance_storeconfiguration optionswift_buffer_on_uploadtoTrueSet the
glance_storeconfiguration optionswift_upload_buffer_dirto a string value representing an absolute directory path. This directory will be used to hold the buffered data.
The Buffered Reader works by taking advantage of the way Swift stores large objects by segmenting them into discrete chunks. Thus, the amount of disk space a Glance API node will require for buffering is a function of the
swift_store_large_object_chunk_sizesetting and the number of worker threads (configured in glance-api.conf as the value ofworkers). Disk utilization will cap at the following valueswift_store_large_object_chunk_size * workers * 1000
Be aware that depending upon how the file system is configured, the disk space used for buffering may decrease the actual disk space available for the Glance image cache, which may affect overall performance.
For more information, see the Buffered Reader for Swift Driver spec.
Upgrade Notes¶
Two new configuration options,
swift_buffer_on_uploadandswift_upload_buffer_dirhave been introduced. These apply only to users of the Swift store and their use is optional. See the New Features section for more information.
