Hi, 1. Durability depends on IGFS mode. In PRIMARY there is no durability, In other modes IGFS will propagate writes to underlying file system (e.g. to HDFS). 2. Files stored in IGFS are always partitioned. You can specify number of backups and/or REPLICATED mode in data cache configuration. 3. Yes, as long as you have Hadoop-compliant implementation of S3 file system (e.g. org.apache.hadoop.fs.s3.S3FileSystem). 4. You can configure evictions from data cache. Please refer to org.apache.ignite.cache.eviction.igfs.IgfsPerBlockLruEvictionPolicy class. 5. Underlying file system must be shared between all nodes in cluster. If it is true, then you can use org.apache.ignite.igfs.secondary.local.LocalIgfsSecondaryFileSystem. 6. You can define pinned files before node start. But you cannot change it in runtime. Please refer to IgfsPerBlockLruEvictionPolicy.setExcludePaths() method. 7. PROXY mode doesn't cache any data, but simply delegates to secondary file system. It is useful when you do not want to cache certain part of data at all. For example, if you access data only once. 8. No. Write-behind speeds up user operations at the cost of consistency guarantees.
On Tue, Jan 24, 2017 at 5:00 PM, pragmaticbigdata <amits...@gmail.com> wrote: > I have some questions of deploying IGFS as a cache layer given that ignite > could be deployed both as a key-value store and as a file system > > 1. How does IGFS behave when deployed in standalone mode? I wanted to > confirm that there is no durability in this mode. Assuming I persist a > parquet file on IGFS, if the cluster goes down I lose the file, right? > 2. Do we get the ability to specify the fact that the file stored in IGFS > could be both partitioned (with backup nodes) or replicated? > 3. IGFS can act as a cache layer over HDFS and local file system, can it > act > as a caching layer over S3 store? > 4. As with the key-value store, can I configure tiered storage in IGFS i.e. > given that IGFS is configured with local file system as the secondary store > and the ignite cluster of 3 server nodes configured with 5GB memory each, > would the data spill over to the local disk if I try to load a 25GB file > into IGFS? If so, what is the configuration needed? > 5. Can I configure local SSD disks as the secondary store for IGFS? > 6. I browsed through the documentation but I didn't find the capability of > pinning and unpinning files in IGFS. I am looking something similar to what > alluxio > <http://www.alluxio.org/docs/master/en/Tiered-Storage-on- > Alluxio.html#pinning-files> > provides. Can it be implemented? > 7. Could you elaborate a bit on how IGFS Proxy Mode works? What is its > recommended use case? > 8. With DUAL_ASYNC (write-behind mode), does ignite have failover > guarantees > which is lacking in the key-value store - > https://issues.apache.org/jira/browse/IGNITE-1897? > > Thanks in advance. > > > > -- > View this message in context: http://apache-ignite-users. > 70518.x6.nabble.com/IGFS-Questions-tp10217.html > Sent from the Apache Ignite Users mailing list archive at Nabble.com. >
