Asias He 5fe2ce3bbe gossiper: Always use the new generation number
User reported an issue that after a node restart, the restarted node
is marked as DOWN by other nodes in the cluster while the node is up
and running normally.

Consier the following:

- n1, n2, n3 in the cluster
- n3 shutdown itself
- n3 send shutdown verb to n1 and n2
- n1 and n2 set n3 in SHUTDOWN status and force the heartbeat version to
  INT_MAX
- n3 restarts
- n3 sends gossip shadow rounds to n1 and n2, in
  storage_service::prepare_to_join,
- n3 receives response from n1, in gossiper::handle_ack_msg, since
  _enabled = false and _in_shadow_round == false, n3 will apply the
  application state in fiber1, filber 1 finishes faster filber 2, it
  sets _in_shadow_round = false
- n3 receives response from n2, in gossiper::handle_ack_msg, since
  _enabled = false and _in_shadow_round == false, n3 will apply the
  application state in fiber2, filber 2 yields
- n3 finishes the shadow round and continues
- n3 resets gossip endpoint_state_map with
  gossiper.reset_endpoint_state_map()
- n3 resumes fiber 2, apply application state about n3 into
  endpoint_state_map, at this point endpoint_state_map contains
  information including n3 itself from n2.
- n3 calls gossiper.start_gossiping(generation_number, app_states, ...)
  with new generation number generated correctly in
  storage_service::prepare_to_join, but in
  maybe_initialize_local_state(generation_nbr), it will not set new
  generation and heartbeat if the endpoint_state_map contains itself
- n3 continues with the old generation and heartbeat learned in fiber 2
- n3 continues the gossip loop, in gossiper::run,
  hbs.update_heart_beat() the heartbeat is set to the number starting
  from 0.
- n1 and n2 will not get update from n3 because they use the same
  generation number but n1 and n2 has larger heartbeat version
- n1 and n2 will mark n3 as down even if n3 is alive.

To fix, always use the the new generation number.

Fixes: #5800
Backports: 3.0 3.1 3.2
(cherry picked from commit 62774ff882)
2020-03-27 12:49:20 +01:00
2020-01-13 13:53:08 +03:00
2020-02-26 18:12:55 +02:00
2019-11-28 16:47:52 +02:00
2020-03-12 19:41:50 +02:00
2019-12-19 15:43:04 +02:00
2020-02-09 18:55:42 +02:00
2020-02-09 18:55:42 +02:00
2019-09-24 10:52:49 +02:00
2019-11-21 15:07:39 +02:00
2020-01-15 15:06:00 +02:00
2020-03-19 21:46:44 +02:00

Scylla

Quick-start

To get the build going quickly, Scylla offers a frozen toolchain which would build and run Scylla using a pre-configured Docker image. Using the frozen toolchain will also isolate all of the installed dependencies in a Docker container. Assuming you have met the toolchain prerequisites, which is running Docker in user mode, building and running is as easy as:

$ ./tools/toolchain/dbuild ./configure.py
$ ./tools/toolchain/dbuild ninja build/release/scylla
$ ./tools/toolchain/dbuild ./build/release/scylla --developer-mode 1

Please see HACKING.md for detailed information on building and developing Scylla.

Note: GCC >= 8.1.1 is required to compile Scylla.

Running Scylla

  • Run Scylla
./build/release/scylla

  • run Scylla with one CPU and ./tmp as work directory
./build/release/scylla --workdir tmp --smp 1
  • For more run options:
./build/release/scylla --help

Scylla APIs and compatibility

By default, Scylla is compatible with Apache Cassandra and its APIs - CQL and Thrift. There is also experimental support for the API of Amazon DynamoDB, but being experimental it needs to be explicitly enabled to be used. For more information on how to enable the experimental DynamoDB compatibility in Scylla, and the current limitations of this feature, see Alternator and Getting started with Alternator.

Documentation

Documentation can be found in ./docs and on the wiki. There is currently no clear definition of what goes where, so when looking for something be sure to check both. Seastar documentation can be found here. User documentation can be found here.

Building Fedora RPM

As a pre-requisite, you need to install Mock on your machine:

# Install mock:
sudo yum install mock

# Add user to the "mock" group:
usermod -a -G mock $USER && newgrp mock

Then, to build an RPM, run:

./dist/redhat/build_rpm.sh

The built RPM is stored in /var/lib/mock/<configuration>/result directory. For example, on Fedora 21 mock reports the following:

INFO: Done(scylla-server-0.00-1.fc21.src.rpm) Config(default) 20 minutes 7 seconds
INFO: Results and/or logs in: /var/lib/mock/fedora-21-x86_64/result

Building Fedora-based Docker image

Build a Docker image with:

cd dist/docker
docker build -t <image-name> .

Run the image with:

docker run -p $(hostname -i):9042:9042 -i -t <image name>

Contributing to Scylla

Hacking howto Guidelines for contributing

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