This commit promotes the Consensus component (and Raft) to become a fully
independent thing like other components, passed to NewCluster during
initialization. Cluster (main component) no longer creates the consensus
layer internally. This has triggered a number of breaking changes
that I will explain below.
Motivation: Future work will require the possibility of running Cluster
with a consensus layer that is not Raft. The "consensus" layer is in charge
of maintaining two things:
* The current cluster peerset, as required by the implementation
* The current cluster pinset (shared state)
While the pinset maintenance has always been in the consensus layer, the
peerset maintenance was handled by the main component (starting by the "peers"
key in the configuration) AND the Raft component (internally)
and this generated lots of confusion: if the user edited the peers in the
configuration they would be greeted with an error.
The bootstrap process (adding a peer to an existing cluster) and configuration
key also complicated many things, since the main component did it, but only
when the consensus was initialized and in single peer mode.
In all this we also mixed the peerstore (list of peer addresses in the libp2p
host) with the peerset, when they need not to be linked.
By initializing the consensus layer before calling NewCluster, all the
difficulties in maintaining the current implementation in the same way
have come to light. Thus, the following changes have been introduced:
* Remove "peers" and "bootstrap" keys from the configuration: we no longer
edit or save the configuration files. This was a very bad practice, requiring
write permissions by the process to the file containing the private key and
additionally made things like Puppet deployments of cluster difficult as
configuration would mutate from its initial version. Needless to say all the
maintenance associated to making sure peers and bootstrap had correct values
when peers are bootstrapped or removed. A loud and detailed error message has
been added when staring cluster with an old config, along with instructions on
how to move forward.
* Introduce a PeerstoreFile ("peerstore") which stores peer addresses: in
ipfs, the peerstore is not persisted because it can be re-built from the
network bootstrappers and the DHT. Cluster should probably also allow
discoverability of peers addresses (when not bootstrapping, as in that case
we have it), but in the meantime, we will read and persist the peerstore
addresses for cluster peers in this file, different from the configuration.
Note that dns multiaddresses are now fully supported and no IPs are saved
when we have DNS multiaddresses for a peer.
* The former "peer_manager" code is now a pstoremgr module, providing utilities
to parse, add, list and generally maintain the libp2p host peerstore, including
operations on the PeerstoreFile. This "pstoremgr" can now also be extended to
perform address autodiscovery and other things indepedently from Cluster.
* Create and initialize Raft outside of the main Cluster component: since we
can now launch Raft independently from Cluster, we have more degrees of
freedom. A new "staging" option when creating the object allows a raft peer to
be launched in Staging mode, waiting to be added to a running consensus, and
thus, not electing itself as leader or doing anything like we were doing
before. This additionally allows us to track when the peer has become a
Voter, which only happens when it's caught up with the state, something that
was wonky previously.
* The raft configuration now includes an InitPeerset key, which allows to
provide a peerset for new peers and which is ignored when staging==true. The
whole Raft initialization code is way cleaner and stronger now.
* Cluster peer bootsrapping is now an ipfs-cluster-service feature. The
--bootstrap flag works as before (additionally allowing comma-separated-list
of entries). What bootstrap does, is to initialize Raft with staging == true,
and then call Join in the main cluster component. Only when the Raft peer
transitions to Voter, consensus becomes ready, and cluster becomes Ready.
This is cleaner, works better and is less complex than before (supporting
both flags and config values). We also backup and clean the state whenever
we are boostrapping, automatically
* ipfs-cluster-service no longer runs the daemon. Starting cluster needs
now "ipfs-cluster-service daemon". The daemon specific flags (bootstrap,
alloc) are now flags for the daemon subcommand. Here we mimic ipfs ("ipfs"
does not start the daemon but print help) and pave the path for merging both
service and ctl in the future.
While this brings some breaking changes, it significantly reduces the
complexity of the configuration, the code and most importantly, the
documentation. It should be easier now to explain the user what is the
right way to launch a cluster peer, and more difficult to make mistakes.
As a side effect, the PR also:
* Fixes#381 - peers with dynamic addresses
* Fixes#371 - peers should be Raft configuration option
* Fixes#378 - waitForUpdates may return before state fully synced
* Fixes#235 - config option shadowing (no cfg saves, no need to shadow)
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
This adds support for parameters to create a libp2p host
in the REST API configuration: ID, PrivateKey and ListenMultiaddr.
These parameters default to nil/empty and are ommited in the default
configuration. They are only supposed to be used when the user wants
the REST API to use a different libp2p host than a provided one (upcoming
changes).
Pnet protector not supported yet in this case. Underlying basic auth
should cover that front. Will implement if someone has a usecase.
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
This fixes#326. It adds a new `pin_method` configuration option to the
`ipfshttp` component allows to configure it to perform `refs -r <cid>` before
the `pin/add` call. By fetching content before pinning, we don't have
a global lock in place, and we can have several pin-requests to
ipfs in parallel.
It also adds a `concurrent_pins` option to the pin tracker, which
launches more pin workers so it can potentially trigger more pins at
the same time. This is a minimal intervention in the pintracker as #308
is still pending.
Documentation for the configuration file has been updated.
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
This enables support for testing in jenkins.
Several minor adjustments have been performed to improve the probability
that the tests pass, but there are still some random
problems appearing with libp2p conections not becoming available or
stopping working (similar to travis, but perhaps more often).
MacOS and Windows builds are broken in worse ways (those issues will
need to be addressed in the future).
Thanks to @zenground0 and @victorbjelkholm for support!
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
This also generates a default configuration section when it
doesn't exist, so it's backwards compatible.
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
The main differences is that the new version of Raft is more strict
about starting raft peers which already contain configurations.
For a start, cluster will fail to start if the configured cluster
peers are different from the Raft peers. The user will have to
manually cleanup Raft (TODO: an ipfs-cluster-service command for it).
Additionally, this commit adds extra options to the consensus/raft
configuration section, adds tests and improves existing ones and
improves certain code sections.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
The following commit reimplements ipfs-cluster configuration under
the following premises:
* Each component is initialized with a configuration object
defined by its module
* Each component decides how the JSON representation of its
configuration looks like
* Each component parses and validates its own configuration
* Each component exposes its own defaults
* Component configurations are make the sections of a
central JSON configuration file (which replaces the current
JSON format)
* Component configurations implement a common interface
(config.ComponentConfig) with a set of common operations
* The central configuration file is managed by a
config.ConfigManager which:
* Registers ComponentConfigs
* Assigns the correspondent sections from the JSON file to each
component and delegates the parsing
* Delegates the JSON generation for each section
* Can be notified when the configuration is updated and must be
saved to disk
The new service.json would then look as follows:
```json
{
"cluster": {
"id": "QmTVW8NoRxC5wBhV7WtAYtRn7itipEESfozWN5KmXUQnk2",
"private_key": "<...>",
"secret": "00224102ae6aaf94f2606abf69a0e278251ecc1d64815b617ff19d6d2841f786",
"peers": [],
"bootstrap": [],
"leave_on_shutdown": false,
"listen_multiaddress": "/ip4/0.0.0.0/tcp/9096",
"state_sync_interval": "1m0s",
"ipfs_sync_interval": "2m10s",
"replication_factor": -1,
"monitor_ping_interval": "15s"
},
"consensus": {
"raft": {
"heartbeat_timeout": "1s",
"election_timeout": "1s",
"commit_timeout": "50ms",
"max_append_entries": 64,
"trailing_logs": 10240,
"snapshot_interval": "2m0s",
"snapshot_threshold": 8192,
"leader_lease_timeout": "500ms"
}
},
"api": {
"restapi": {
"listen_multiaddress": "/ip4/127.0.0.1/tcp/9094",
"read_timeout": "30s",
"read_header_timeout": "5s",
"write_timeout": "1m0s",
"idle_timeout": "2m0s"
}
},
"ipfs_connector": {
"ipfshttp": {
"proxy_listen_multiaddress": "/ip4/127.0.0.1/tcp/9095",
"node_multiaddress": "/ip4/127.0.0.1/tcp/5001",
"connect_swarms_delay": "7s",
"proxy_read_timeout": "10m0s",
"proxy_read_header_timeout": "5s",
"proxy_write_timeout": "10m0s",
"proxy_idle_timeout": "1m0s"
}
},
"monitor": {
"monbasic": {
"check_interval": "15s"
}
},
"informer": {
"disk": {
"metric_ttl": "30s",
"metric_type": "freespace"
},
"numpin": {
"metric_ttl": "10s"
}
}
}
```
This new format aims to be easily extensible per component. As such,
it already surfaces quite a few new options which were hardcoded
before.
Additionally, since Go API have changed, some redundant methods have been
removed and small refactoring has happened to take advantage of the new
way.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
The disk informer uses "ipfs repo stat" to fetch the RepoSize value and
uses it as a metric.
The numpinalloc allocator is now a generalized ascendalloc which
sorts metrics in ascending order and return the ones with lowest
values.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
An initial, simple approach to this. The PeerMonitor will
check it's metrics, compare to the current set of peers and put
an alert in the alerts channel if the metrics for a peer have expired.
Cluster reads this channel looking for "ping" alerts. The leader
is in charge of triggering repins in all the Cids allocated to
a given peer.
Also, metrics are now broadcasted to the cluster instead of pushed only
to the leader. Since they happen every few seconds it should be okay
regarding how it scales. Main problem was that if the leader is the node
going down, the new leader will not now about it as it doesn't have any
metrics for it, so it won't trigger an alert. If it acted on that then
the component needs to know it is the leader, or cluster needs to
handle alerts in complicated ways when leadership changes. Detecting
leadership changes or letting a component know who is the leader is another
dependency from the consensus algorithm that should be avoided. Therefore
we broadcast, for the moment.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
This is the third implementation attempt. This time, rather than
broadcasting PeerAdd/Join requests to the whole cluster, we use the
consensus log to broadcast new peers joining.
This makes it easier to recover from errors and to know who exactly
is member of a cluster and who is not. The consensus is, after all,
meant to agree on things, and the list of cluster peers is something
everyone has to agree on.
Raft itself uses a special log operation to maintain the peer set.
The tests are almost unchanged from the previous attempts so it should
be the same, except it doesn't seem possible to bootstrap a bunch of nodes
at the same time using different bootstrap nodes. It works when using
the same. I'm not sure this worked before either, but the code is
simpler than recursively contacting peers, and scales better for
larger clusters.
Nodes have to be careful about joining clusters while keeping the state
from a different cluster (disjoint logs). This may cause problems with
Raft.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
This commit adds PeerAdd() and PeerRemove() endpoints, CLI support,
tests. Peer management is a delicate issue because of how the consensus
works underneath and the places that need to track such peers.
When adding a peer the procedure is as follows:
* Try to open a connection to the new peer and abort if not reachable
* Broadcast a PeerManagerAddPeer operation which tells all cluster members
to add the new Peer. The Raft leader will add it to Raft's peerset and
the multiaddress will be saved in the ClusterPeers configuration key.
* If the above fails because some cluster node is not responding,
broadcast a PeerRemove() and try to undo any damage.
* If the broadcast succeeds, send our ClusterPeers to the new Peer along with
the local multiaddress we are using in the connection opened in the
first step (that is the multiaddress through which the other peer can reach us)
* The new peer updates its configuration with the new list and joins
the consensus
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
