Node (sync)¶

class aerospike_sdk.sync.node.Node[source]¶

Bases: NodeBase

One server node of a connected cluster (synchronous).

Obtained from Cluster.nodes or Cluster.get_node. Properties and aliases() read state the client already holds; info() sends a command to this node specifically, which a cluster-wide info call cannot do.

Example:

for node in cluster.nodes():
    build = node.info("build")["build"]
    print(f"{node.name} {node.address}: {build}")

See also

aerospike_sdk.aio.node.Node: The async counterpart. InfoCommands: Parsed cluster-wide info.

info(command)[source]¶

Run a raw info command on this node only.

Example:

node = cluster.get_node("BB9D4EB574A8DA6")
roster = node.info("roster:namespace=test")
print(roster["roster:namespace=test"])

Parameters:: command (str) – The info command, e.g. "build" or "namespace/test".
Return type:: Dict[str, str]
Returns:: The response keyed by command. A command the server rejects comes back as an ERROR:... value, not as an exception.
Raises:: AerospikeError – If the node cannot be reached.

See also

InfoCommands.info_on_all_nodes: The same command on every node at once.

__init__(pnc_node)¶: Wrap a PNC node; obtained from Cluster.nodes or Cluster.get_node.

property address: str¶

The host:port address the client connects to for this node.

Example:

print(f"{node.name} at {node.address}")   # BB9D4EB574A8DA6 at 10.0.0.12:3000

Returns:: The address as "host:port".

See also

host: The same address as a (host, port) tuple.

aliases()¶

Every (host, port) the client has seen this node answer on.

A node reached through several addresses (seed hostname, peer-reported IP, alternate services address) is one node with several aliases.

Example:

for hostname, port in node.aliases():
    print(f"{node.name} reachable at {hostname}:{port}")

Return type:: List[Tuple[str, int]]
Returns:: The node’s known addresses, including host.

See also

host: The address the client currently connects to.

property failures: int¶

Failures the client has counted for this node since its last successful refresh.

Example:

flaky = [node.name for node in cluster.nodes() if node.failures > 0]

Returns:: The failure count; 0 for a healthy node, and reset to 0 by the next successful cluster tend.

See also

is_active: Whether the node is still in the cluster.

property host: Tuple[str, int]¶

The address the client connects to, as a (host, port) tuple.

Example:

hostname, port = node.host
assert port != 4333, "still connected over TLS"

Returns:: (hostname, port).

See also

address: The same address as a string.

property is_active: bool¶

Whether the client still considers this node part of the cluster.

A node object outlives its membership: one fetched before the node left keeps reporting its last-known state here as False.

Example:

inactive = [node.name for node in cluster.nodes() if not node.is_active]

Returns:: True while the node is in the client’s current node list.

See also

Cluster.nodes(): The current, active node list.

property name: str¶

The server-assigned node ID, e.g. "BB9D4EB574A8DA6".

This is the key Cluster.get_node() looks up, and the key the *_per_node info helpers return results under.

Example:

names = [node.name for node in cluster.nodes()]

Returns:: The node’s name.

See also

address: Where the client reaches this node.

property partition_generation: int¶

The node’s partition-map generation, bumped when its partition ownership changes.

Example:

generations = {node.name: node.partition_generation for node in cluster.nodes()}

Returns:: The generation the client last read from the node.

See also

rebalance_generation: The generation for rebalance events.

property rebalance_generation: int¶

The node’s rebalance generation, bumped each time the cluster rebalances.

Example:

generations = {node.rebalance_generation for node in cluster.nodes()}
settled = len(generations) == 1

Returns:: The generation the client last read from the node.

See also

partition_generation: The generation for partition-map changes.

property version: Version¶

The server version this node runs.

Per-node, unlike Cluster.server_version(), which reports the cluster minimum. Comparing them across nodes shows whether a rolling upgrade has finished.

Example:

versions = {node.name: str(node.version) for node in cluster.nodes()}
if len(set(versions.values())) > 1:
    print(f"mixed-version cluster: {versions}")

Returns:: The node’s Version.

See also

Cluster.server_version(): The minimum across all nodes.