Read Cache
fx882
17 Posts
November 2, 2017, 4:38 pmQuote from fx882 on November 2, 2017, 4:38 pmIs there any point on the roadmap for a read cache?
There is a discussion using bcache as read cache(Here: Re: Ceph OSDs with bcache experience — CEPH Filesystem Users ). Since the cache-tiering of ceph seems complex and not appropriate as a general read cache, a simple read cache functionality using fast persistent storage(ssd) is completely missing in ceph(does nobody miss it?) and could boost performance especially on smaller installations i assume.
Is there any point on the roadmap for a read cache?
There is a discussion using bcache as read cache(Here: Re: Ceph OSDs with bcache experience — CEPH Filesystem Users ). Since the cache-tiering of ceph seems complex and not appropriate as a general read cache, a simple read cache functionality using fast persistent storage(ssd) is completely missing in ceph(does nobody miss it?) and could boost performance especially on smaller installations i assume.
Last edited on November 2, 2017, 4:42 pm by fx882 · #1
admin
2,921 Posts
November 3, 2017, 8:56 amQuote from admin on November 3, 2017, 8:56 amYes definitely we will do this. Although some Ceph users have come up with their own bcache configuration, it is the intention of the Ceph to look into using bcache(or dm-cache/flashcache) for caching the data device in Bluestore engine and see their performance and possibly decide if they need to develop something custom for Ceph or not. So there will be performance work and recommendations in this area but i do not expect it will be very soon as still Bluestore is quite new. Note for PetaSAN the upcoming version 1.5 will support ssd/nvme journals and version 2.0 will support Bluestore with wal/rocksdb placed on faster ssd/nvme devices.. but caching with bcache will have to wait as per above.
Yes definitely we will do this. Although some Ceph users have come up with their own bcache configuration, it is the intention of the Ceph to look into using bcache(or dm-cache/flashcache) for caching the data device in Bluestore engine and see their performance and possibly decide if they need to develop something custom for Ceph or not. So there will be performance work and recommendations in this area but i do not expect it will be very soon as still Bluestore is quite new. Note for PetaSAN the upcoming version 1.5 will support ssd/nvme journals and version 2.0 will support Bluestore with wal/rocksdb placed on faster ssd/nvme devices.. but caching with bcache will have to wait as per above.
Read Cache
fx882
17 Posts
Quote from fx882 on November 2, 2017, 4:38 pmIs there any point on the roadmap for a read cache?
There is a discussion using bcache as read cache(Here: Re: Ceph OSDs with bcache experience — CEPH Filesystem Users ). Since the cache-tiering of ceph seems complex and not appropriate as a general read cache, a simple read cache functionality using fast persistent storage(ssd) is completely missing in ceph(does nobody miss it?) and could boost performance especially on smaller installations i assume.
Is there any point on the roadmap for a read cache?
There is a discussion using bcache as read cache(Here: Re: Ceph OSDs with bcache experience — CEPH Filesystem Users ). Since the cache-tiering of ceph seems complex and not appropriate as a general read cache, a simple read cache functionality using fast persistent storage(ssd) is completely missing in ceph(does nobody miss it?) and could boost performance especially on smaller installations i assume.
admin
2,921 Posts
Quote from admin on November 3, 2017, 8:56 amYes definitely we will do this. Although some Ceph users have come up with their own bcache configuration, it is the intention of the Ceph to look into using bcache(or dm-cache/flashcache) for caching the data device in Bluestore engine and see their performance and possibly decide if they need to develop something custom for Ceph or not. So there will be performance work and recommendations in this area but i do not expect it will be very soon as still Bluestore is quite new. Note for PetaSAN the upcoming version 1.5 will support ssd/nvme journals and version 2.0 will support Bluestore with wal/rocksdb placed on faster ssd/nvme devices.. but caching with bcache will have to wait as per above.
Yes definitely we will do this. Although some Ceph users have come up with their own bcache configuration, it is the intention of the Ceph to look into using bcache(or dm-cache/flashcache) for caching the data device in Bluestore engine and see their performance and possibly decide if they need to develop something custom for Ceph or not. So there will be performance work and recommendations in this area but i do not expect it will be very soon as still Bluestore is quite new. Note for PetaSAN the upcoming version 1.5 will support ssd/nvme journals and version 2.0 will support Bluestore with wal/rocksdb placed on faster ssd/nvme devices.. but caching with bcache will have to wait as per above.