Before we relied on the global cluster state to make sure all the hash
slots are linked to some node, when getNodeByQuery() is called. So
finding the hash slot unbound was checked with an assertion. However
this is fragile. The cluster state is often updated in the
clusterBeforeSleep() function, and not ASAP on state change, so it may
happen to process clients with a cluster state that is 'ok' but yet
certain hash slots set to NULL.
With this commit the condition is also checked in getNodeByQuery() and
reported with a identical error code of -CLUSTERDOWN but slightly
different error message so that we have more debugging clue in the
future.
Root cause of issue #2288.
Less grays: more readable palette since usually we have a non linear
distribution of percentages and very near gray tones are hard to take
apart. Final part of the palette is gradient from yellow to red. The red
part is hardly reached because of usual distribution of latencies, but
shows up mainly when latencies are very high because of the logarithmic
scale, this is coherent to what people expect: red = bad.
When trying to debug sentinel connections or max connections errors it
would be very useful to have the ability to see the list of connected
clients to a running sentinel. At the same time it would be very helpful
to be able to name each sentinel connection or kill offending clients.
This commits adds the already defined CLIENT commands back to Redis
Sentinel.
1. Remove useless "cs" initialization.
2. Add a "select" var to capture a condition checked multiple times.
3. Avoid duplication of the same if (!copy) conditional.
4. Don't increment dirty if copy is given (no deletion is performed),
otherwise we propagate MIGRATE when not needed.
--stat mode already used to reconnect automatically if the server is no
longer available. This is useful since this is an interactive mode used
for debugging, however the same applies to --latency and --latency-dist
modes, so now both use the reconnecting command execution as well.
The reconnection code was modified to use basic VT100 escape sequences
in order to play better with different kinds of output on the screen
when the reconnection happens, and to hide the reconnection attempt
output when finally the reconnection happens.
So far not able to find a color palette within the 256 colors which is
not confusing. However I believe it is a possible task, so will try
better later.
This test on Linux was extremely slow, since in Tcl we can't enable
easily tcp-nodelay, so the busy loop used to take *a lot* with bigger
writes. Fixed using pipelining.
