RESTORE: accept RDB dumps with older versions.

Reference issue #3218.

Checking the code I can't find a reason why the original RESTORE
code was so opinionated about restoring only the current versi

RESTORE: accept RDB dumps with older versions.

Reference issue #3218.

Checking the code I can't find a reason why the original RESTORE
code was so opinionated about restoring only the current version. The
code in to `rdb.c` appears to be capable as always to restore data from
older versions of Redis, and the only places where it is needed the
current version in order to correctly restore data, is while loading the
opcodes, not the values itself as it happens in the case of RESTORE.

For the above reasons, this commit enables RESTORE to accept older
versions of values payloads.

show more ...

Cluster: make getNodeByQuery() responsible of -CLUSTERDOWN errors.

This fixes a bug introduced by d827dbf, and makes the code consistent
with the logic of always allowing, while the cluster is down,

Cluster: make getNodeByQuery() responsible of -CLUSTERDOWN errors.

This fixes a bug introduced by d827dbf, and makes the code consistent
with the logic of always allowing, while the cluster is down, commands
that don't target any key.

As a side effect the code is also simpler now.

show more ...

Fixes a typo

New masters with slots are now targets of migration if others are.

This fixes issue #3043.

Before this fix, after a complete resharding of a master slots
to other nodes, the master remains empty an

New masters with slots are now targets of migration if others are.

This fixes issue #3043.

Before this fix, after a complete resharding of a master slots
to other nodes, the master remains empty and the slaves migrate away
to other masters with non-zero nodes. However the old master now empty,
is no longer considered a target for migration, because the system has
no way to tell it had slaves in the past.

This fix leaves the algorithm used in the past untouched, but adds a
new rule. When a new or old master which is empty and without slaves,
are assigend with their first slot, if other masters in the cluster have
slaves, they are automatically considered to be targets for replicas
migration.

show more ...

Cluster: include node IDs in SLOTS output.

CLUSTER SLOTS now includes IDs in the nodes description associated with
a given slot range. Certain client libraries implementations need a way
to referenc

Cluster: include node IDs in SLOTS output.

CLUSTER SLOTS now includes IDs in the nodes description associated with
a given slot range. Certain client libraries implementations need a way
to reference a node in an unique way, so they were relying on CLUSTER
NODES, that is not a stable API and may change frequently depending on
Redis Cluster future requirements.

show more ...

Cluster: mismatch sender ID log put back at DEBUG level.

Cluster: fix missing ntohs() call to access gossip section port.

Better address udpate strategy when processing gossip sections.

The change covers the case where:

1. There is a node we can't reach (in fail or pfail state).
2. We see a different address for this

Better address udpate strategy when processing gossip sections.

The change covers the case where:

1. There is a node we can't reach (in fail or pfail state).
2. We see a different address for this node, in the gossip section sent
to us by a node that, instead, is able to talk with the node we cannot
talk to.

In this case it's a good bet to switch to the address reported by this
node, since there was an address switch and it is able to talk with the
node and we are not.

However previosuly this was done in a dangerous way, by initiating an
handshake. The handshake, using the MEET packet, forces the receiver to
join our cluster, and this is not a good idea. If the node in question
really just switched address, but is the same node, it already knows about
us, so we just need to perform an address update and a reconnection.

So with this commit instead we just update the address of the node,
release the node link if any, and attempt to reconnect in the next
clusterCron() cycle.

The commit also improves debugging messages printed by Cluster during
address or ID switches.

show more ...

Minor MIGRATE refactoring.

Centralize cleanup of newargv in a single place.
Add more comments to help a bit following a complex function.

Related to issue #3016.

More variadic MIGRATE fixes.

Another leak was fixed in the case of syntax error by restructuring the
allocation strategy for the two dynamic vectors.

We also make sure to always close the cached so

More variadic MIGRATE fixes.

Another leak was fixed in the case of syntax error by restructuring the
allocation strategy for the two dynamic vectors.

We also make sure to always close the cached socket on I/O errors so that
all the I/O errors are handled the same, even if we had a previously
queued error of a different kind from the destination server.

Thanks to Kevin McGehee. Related to issue #3016.

show more ...

Various fixes to MIGRATE with multiple keys.

In issue #3016 Kevin McGehee identified multiple very serious issues in
the new implementation of MIGRATE. This commit attempts to restructure
the code i

Various fixes to MIGRATE with multiple keys.

In issue #3016 Kevin McGehee identified multiple very serious issues in
the new implementation of MIGRATE. This commit attempts to restructure
the code in oder to avoid mistakes, an analysis of the new
implementation is in progress in order to check for possible edge cases.

show more ...

Cluster: fix setting nodes slaveof pointer to NULL on node release.

With this commit we preserve the list of nodes that have .slaveof set
to the node, even when the node is turned into a slave, and

Cluster: fix setting nodes slaveof pointer to NULL on node release.

With this commit we preserve the list of nodes that have .slaveof set
to the node, even when the node is turned into a slave, and make sure to
fix the .slaveof pointers to NULL when a node is freed from memory,
regardless of the fact it's a slave or a master.

Basically we try to remember the logical master in the current
configuration even if the logical master advertised it as a slave
already. However we still remember the associations, so that when a node
is freed we can fix them.

This should fix issue #3002.

show more ...

CLUSTER BUMPEPOCH initial implementation fixed.

Cluster: CLUSTER BUMPEPOCH introduced to help redis-trib fix.

Sometimes during "fixes" we have to setup a new configuration and assign
slots to nodes. With BUMPEPOCH we can make sure the new configu

Cluster: CLUSTER BUMPEPOCH introduced to help redis-trib fix.

Sometimes during "fixes" we have to setup a new configuration and assign
slots to nodes. With BUMPEPOCH we can make sure the new configuration of
the node will win if there are conflicting configurations (for example
another node is *also* claiming the same slot because the cluster is
totally messed up).

show more ...

Cluster: don't allow CLUSTER SETSLOT with slaves.

Cluster: check packets length before accessing far fields.

Allow MIGRATE to always be called on local keys for open slots.

Extend the MIGRATE extra freedom to be able to be called in the context
of the local slot, anytime there is a slot open in one or the

Allow MIGRATE to always be called on local keys for open slots.

Extend the MIGRATE extra freedom to be able to be called in the context
of the local slot, anytime there is a slot open in one or the other
direction (importing or migrating). This is useful for redis-trib to fix
the cluster when it has in an odd state.

Thix fix allows "redis-trib fix" to make its work in certain cases where
previously an error was reported.

show more ...

Fix typos & grammar in clusterBumpConfigEpochWithoutConsensus() comment.

Cluster: don't send -ASK to MIGRATE.

For non existing keys, we don't want to send -ASK redirections to
MIGRATE, since when moving slots from the migrating node to the
importing node, we want just to

Cluster: don't send -ASK to MIGRATE.

For non existing keys, we don't want to send -ASK redirections to
MIGRATE, since when moving slots from the migrating node to the
importing node, we want just to ignore keys that are no longer there.
They may be expired or deleted between the GETKEYSINSLOT call and the
MIGRATE call. Otherwise this causes an error during migrations with
redis-trib (or equivalent cluster management tools).

show more ...

Suppress harmless warnings.

MIGRATE: Fix new argument rewriting refcount handling.

MIGRATE: fix replies processing and argument rewriting.

We need to process replies after errors in order to delete keys
successfully transferred. Also argument rewriting was fixed since
it was broke

MIGRATE: fix replies processing and argument rewriting.

We need to process replies after errors in order to delete keys
successfully transferred. Also argument rewriting was fixed since
it was broken in several ways. Now a fresh argument vector is created
and set if we are acknowledged of at least one key.

show more ...

Pipelined multiple keys MIGRATE.

Cluster: replica migration with delay.

We wait a fixed amount of time (5 seconds currently) much greater than
the usual Cluster node to node communication latency, before migrating.
This way when a

Cluster: replica migration with delay.

We wait a fixed amount of time (5 seconds currently) much greater than
the usual Cluster node to node communication latency, before migrating.
This way when a failover occurs, before detecting the new master as a
target for migration, we give the time to its natural slaves (the slaves
of the failed over master) to announce they switched to the new master,
preventing an useless migration operation.

show more ...

Remove debugging message left there for error.