51–60 of 120 posts
Is metadata also replicated in S3? Else I don't understand how the metadata can be persistent after reboot as AFAIK redis cannot dump and reload its state.
The is an ongoing effort [1] to improve the persistency and availability in general, which is expected to be GA in 2021.
Is metadata also replicated in S3? Else I don't understand how the metadata can be persistent after reboot as AFAIK redis cannot dump and reload its state.
I'm the founder of JuiceFS, would like to answer any questions here.
I think the major problem is latency. Try sshfs (fs over ssh) and see what I mean. Don't get me wrong, I use and like sshfs for a quick data transfer, but it's just not good enough to run your application with. For a stable POSIX filesystem in production latency is key. Often times in a datacenter 10GE is recommended for network storage solutions, not because of bandwidth (which is also important), but for the 10x re…
Good, that's why we choose Redis for the metadata. When Redis is deployed in same DC or VPC, the latency could be about 0.2ms - 0.5ms. Later on, We will try the client cache of Redis, which could also reduce the latency for some metadata operations down to a few microseconds.
I think the major problem is latency. Try sshfs (fs over ssh) and see what I mean. Don't get me wrong, I use and like sshfs for a quick data transfer, but it's just not good enough to run your application with. For a stable POSIX filesystem in production latency is key. Often times in a datacenter 10GE is recommended for network storage solutions, not because of bandwidth (which is also important), but for the 10x re…
Good, that's why we choose Redis for the metadata. When Redis is deployed in same DC or VPC, the latency could be about 0.2ms - 0.5ms. Later on, We will try the client cache of Redis, which could also reduce the latency for some metadata operations down to a few microseconds.
Now you could say, that I could host my own S3 e.g. MinIO in the same DC, but then I could also simply deploy Ceph, which is battle tested for years up to the petabyte range and with iSCSI, S3 and FS interfaces.
So I think this project might give the wrong impression that you can simply combine a Redis with Amazon S3 and then have a good FS solution available, which is unfortunately not the case.
I think the major problem is latency. Try sshfs (fs over ssh) and see what I mean. Don't get me wrong, I use and like sshfs for a quick data transfer, but it's just not good enough to run your application with. For a stable POSIX filesystem in production latency is key. Often times in a datacenter 10GE is recommended for network storage solutions, not because of bandwidth (which is also important), but for the 10x re…
Totally true. In those cases you also need your filer _not_ to compress on the fly, and not deduplicate objects... unless your hardware can do it for you.
... I remember horrible performance on VMs with images stored on a oversized netapp filer, because someone enabled deduplication and compression instead of using 1 of the 4 spare drives (when it was HDD).
Earlier quoted context omitted.
Good, that's why we choose Redis for the metadata. When Redis is deployed in same DC or VPC, the latency could be about 0.2ms - 0.5ms. Later on, We will try the client cache of Redis, which could also reduce the latency for some metadata operations down to a few microseconds.
A low latency metadata server is good, but you still have the latency to the S3 server, e.g. Amazon S3 (from your README.md). Now you could say, that I could host my own S3 e.g. MinIO in the same DC, but then I could also simply deploy Ceph, which is battle tested for years up to the petabyte range and with iSCSI, S3 and FS interfaces. So I think this project might give the wrong impression that you can simply combin…
Ceph is great, if you can master the complexity under the hood, MinIO + Redis + JuiceFS could be the easier answer for beginners.
Some of those things don't appear to be covered by pjdfstest.