Nodes

A store becomes a node when serve is given --node-listen or --from: it keeps a log of each file it writes, serves those files to other nodes, and copies the files of the node it takes from. Every file has one home that writes it; copies read locally and pass their writes home. The commands here start nodes, show how they stand, and move a home when one is gone.

# the home
tinystore serve ./us --node-listen 0.0.0.0:7444 --node-config node.toml
# a copy of every file of the home
tinystore serve ./eu --from us.internal:7444 --node-listen 0.0.0.0:7444 --node-config node.toml

token-file = "/etc/tinystore/node-token" # the token nodes show each other
advertise = "eu.internal:7444"           # where other nodes reach this one

[tls]
cert = "/etc/tinystore/node.pem"
key = "/etc/tinystore/node.key"
roots = "/etc/tinystore/ca.pem"

The config's rarer keys: files, token-file, catalog, advertise, synchronous, synchronous-with, failover, insecure and [tls]'s cert, key and roots. A link beyond its own machine takes TLS unless insecure = true.

#node status

tinystore node status ./eu
tinystore node status ./eu --json

It shows the node's files, which it writes and which it copies, its links, and how far behind its home each copy is. It reads beside the running node.

#promote and demote

When a home is gone and will not come back soon, a person promotes a copy:

# stop the copy's server first
tinystore node promote ./eu --from us.internal:7444
tinystore serve ./eu --node-listen 0.0.0.0:7444 --node-config node.toml # without --from: it is the home now

• The node must be stopped.
• promote asks each node named by --from first. One that still serves the file would make a second home, so the promotion is refused unless --force.
• Commits the old home had not shipped are lost with it, unless the home was synchronous. demote drops, counts and logs the ones the old home still holds, and follows the new home before it opens a writer.

tinystore node demote ./us
tinystore serve ./us --from eu.internal:7444 --node-listen 0.0.0.0:7444 --node-config node.toml

#witness

A draft: a witness keeps each file's lease and no data, and gives the lease to the freshest copy when a home goes quiet. Nodes name it as failover in their config.

tinystore witness ./witness --listen 0.0.0.0:7445 --token-file token

#See also

• The command line.
• Readers in another region and When a home dies in the Handbook.