This commit continues the work of taking advantage of the streaming
capabilities in go-libp2p-gorpc by improving the ipfsconnector and pintracker
components.
StatusAll and RecoverAll methods are now streaming methods, with the REST API
output changing accordingly to produce a stream of GlobalPinInfos rather than
a json array.
pin/ls request to the ipfs daemon now use ?stream=true and avoid having to
load the full pinset map on memory. StatusAllLocal and RecoverAllLocal
requests to the pin tracker stream all the way and no longer store the full
pinset, and the full PinInfo status slice before sending it out.
We have additionally switched to a pattern where streaming methods receive the
channel as an argument, allowing the caller to decide on whether to launch a
goroutine, do buffering etc.
This commit introduces the new go-libp2p-gorpc streaming capabilities for
Cluster. The main aim is to work towards heavily reducing memory usage when
working with very large pinsets.
As a side-effect, it takes the chance to revampt all types for all public
methods so that pointers to static what should be static objects are not used
anymore. This should heavily reduce heap allocations and GC activity.
The main change is that state.List now returns a channel from which to read
the pins, rather than pins being all loaded into a huge slice.
Things reading pins have been all updated to iterate on the channel rather
than on the slice. The full pinset is no longer fully loaded onto memory for
things that run regularly like StateSync().
Additionally, the /allocations endpoint of the rest API no longer returns an
array of pins, but rather streams json-encoded pin objects directly. This
change has extended to the restapi client (which puts pins into a channel as
they arrive) and to ipfs-cluster-ctl.
There are still pending improvements like StatusAll() calls which should also
stream responses, and specially BlockPut calls which should stream blocks
directly into IPFS on a single call.
These are coming up in future commits.
Badger can take 1000x the amount of needed space if not GC'ed or compacted
(#1320), even for non heavy usage. Cluster has no provisions to run datastore
GC operations and while they could be added, they are not ensured to
help. Improvements on Badger v3 might help but would still need to GC
explicitally.
Cluster was however designed to support any go-datastore as backend.
This commit adds LevelDB support. LevelDB go-datastore wrapper is mature, does
not need GC and should work well for most cluster usecases, which are not
overly demanding.
A new `--datastore` flag has been added on init. The store backend is selected
based on the value in the configuration, similar to how raft/crdt is. The
default is set to leveldb. From now on it should be easier to add additional
backends, i.e. badgerv3.
For the online case we were unnecessarily loading the configuration from IPFS, a very
slow operation if IPFS is very busy (when syncing).
For the offline case, we required IPFS to be online (for remote
configurations) slow things down as well and is uncovenient. Instead, simply
open the database with default parameters and list it.
Fixes#865.
This makes the necessary changes so that consensu is selected on "init" with a
flag set, by default, to "crdt". This generates only a "crdt" or a "raft"
section, not both.
If the configuration file has a "raft" section, "raft" will be used to start
the daemon. If it has a "crdt" section, "crdt" will be used. If it has none or
both sections, an error will happen.
This also affects "state *" commands, which will now autoselect how to work
from the existing configuration.
* Daemon: support remote configuration
This:
* Adds support for fetching the configuration from a remote HTTP location:
`ipfs-cluster-service init http://localhost:8080/ipfs/Qm...` will instruct
cluster to read the configuration file from ipfs on start (potentially making
use of ipns and dnslink).
This is done by creating a `service.json` like `{ "source": <url> }`.
The source is then read when loading that configuration every time the daemon starts.
This allows to let users always use a mutating remote configuration, potentially
adding/removing trusted peers from the list or adjusting other things.
* Configuration and state helpers from ipfs-cluster-service have been extracted
to its own cmdutils package. This will help supporting something like an
`ipfs-cluster-follow` command in the next releases.
* Allows to disable the rest api by not defining it in the configuration (I thought
this was already so, but apparently only affected the ipfsproxy).
* Removes informer/allocator configurations from the daemon (--alloc). No one used
a non default pair. In fact, it was potentially buggy to use the reposize one.
