Today I realised that although we have per-table metrics, they are not
*really* available by default. I was suprised to find that we don't have
(as far as I can tell) a document explaining why it is so, or how to enable
them anyway. Moreover, the more I investigated this issue, the more I
realised how little I know on Scylla's metrics - how they are calculated,
how they are collected, their different types, and so on.
So I sat down to figure out everything I wanted to learn about Scylla metrics,
and then wrote it all down in a new document, docs/metrics.md.
There are some missing pieces in this document marked by TODO, and probably
additional missing pieces that I'm not aware of, but I think this is already
a good start and can be (and should be) improved-on later.
We really need to have more of these documents describing various Scylla
subsystems to new developers - what each subsystem does, why it does what
it does, where is the code, and so on. I am facing these problems every
day as a seasoned developer - I can't even imagine what our new developers
face when trying to understand a subsystem they are not yet familiar with.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20180920131103.20590-1-nyh@scylladb.com>
For some reason the doc entry for large_partitions was outdated.
It contained incorrect ORDERING information and wrong usage example,
since large_partitions' schema changed multiple times during
the reviewing process.
Message-Id: <1910f270419536ebccffde163ec1bfc67d273306.1533128957.git.sarna@scylladb.
com>
By default Scylla docker runs without the security features.
This patch adds support for the user to supply different params values for the
authenticator and authorizer classes and allowing to setup a secure Scylla in
Docker.
For example if you want to run a secure Scylla with password and authorization:
docker run --name some-scylla -d scylladb/scylla --authenticator
PasswordAuthenticator --authorizer CassandraAuthorizer
Update the Docker documentation with the new command line options.
Signed-off-by: Noam Hasson <noam@scylladb.com>
Message-Id: <20180620122340.30394-1-noam@scylladb.com>
By default, overprovisioned is not enabled on docker unless it is
explicitly set. I have come to believe that this is a mistake.
If the user is running alone in the machine, and there are no other
processes pinned anywhere - including interrupts - not running
overprovisioned is the best choice.
But everywhere else, it is not: even if a user runs 2 docker containers
in the same machine and statically partitions CPUs with --smp (but
without cpuset) the docker containers will pin themselves to the same
sets of CPU, as they are totally unaware of each other.
It is also very common, specially in some virtualized environments, for
interrupts not to be properly distributed - being particularly keen on
being delivered on CPU0, a CPU which Scylla will pin by default.
Lastly, environments like Kubernetes simply don't support pinning at the
moment.
This patch enables the overprovisioned flag if it is explicitly set -
like we did before - but also by default unless --cpuset is set.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20180331142131.842-1-glauber@scylladb.com>
"
The configuration API is part of scylla v2 configuration.
It uses the new definition capabilities of the API to dynamically create
the swagger definition for the configuration.
This mean that the swagger will contain an entry with description and
type for each of the config value.
To get the v2 of the swager file:
http://localhost:10000/v2
If using with swagger ui, change http://localhost:10000/api-doc to http://localhost:10000/v2
It takes longer to load because the file is much bigger now.
"
* 'amnon/config_api_v5' of github.com:scylladb/seastar-dev:
Explanation about the API V2
API: add the config API as part of the v2 API.
Defining the config api
This patch takes a modified version of the Ubuntu 14.04 housekeeping
service script and uses it in Docker to validate the current version.
To disable the version validation, pass the --disable-version-check flag
when running the container.
Message-Id: <20180220161231.1630-1-amnon@scylladb.com>
This change allows for seamless migration of the legacy users metadata
to the new role-based metadata tables. This process is summarized in
`docs/migrating-from-users-to-roles.md`.
In general, if any nondefault metadata exists in the new tables, then
no migration happens. If, in this case, legacy metadata still exists
then a warning is written to the log.
If no nondefault metadata exists in the new tables and the legacy tables
exist, then each node will copy the data from the legacy tables to the
new tables, performing transformations as necessary. An informational
message is written to the log when the migration process starts, and
when the process ends. During the process of copying, data is
overwritten so that multiple nodes racing to migrate data do not
conflict.
Since Apache Cassandra's auth. schema uses the same table for managing
roles and authentication information, some useful functions in
`roles-metadata.hh` have been added to avoid code duplication.
Because a superuser should be able to drop the legacy users tables from
`system_auth` once the cluster has migrated to roles and is functioning
correctly, we remove the restriction on altering anything in the
"system_auth" keyspace. Individual tables in `system_auth` are still
protected later in the function.
When a cluster is upgrading from one that does not support roles to one
that does, some nodes will be running old code which accesses old
metadata and some will be running new code which access new metadata.
With the help of the gossiper `feature` mechanism, clients connecting to
upgraded nodes will be notified (through code in the relevant CQL
statements) that modifications are not allowed until the entire cluster
has upgraded.
Hinted Handoff is a feature that allows replaying failed writes.
The mutation and the destination replica are saved in a log and replayed
later according to the feature configuration.
Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
Using --hostname to give the container a meaningful name is a good
practice, and make the monitoring dashboard easier to understand
Signed-off-by: Tzach Livyatan <tzach@scylladb.com>
Message-Id: <20170803081027.6675-1-tzach@scylladb.com>
"
- Introduce a parent span IP and span ID paradigm.
- Introduce time series tables to simplify traces processing.
- Add the "How to get traces?" chapter to the tracing.md.
"
* 'tracing-span-ids-and-time-series-helpers-v4' of github.com:cloudius-systems/seastar-dev:
docs: tracing.md: add a "how to get traces" chapter
tracing::trace_keyspace_helper: introduce a time series helper tables
tracing: cleanup: use nullptr instead of trace_state_ptr()
tracing: introduce a span ID and parent span ID
Glauber "eagle eyes" Costa pointed out that the Scylla logo used in our
Docker image documentation looks broken because it's missing the Scylla
text.
Fix the problem by using the Scylla mascot instead.
Message-Id: <1471525154-2800-1-git-send-email-penberg@scylladb.com>
The bug tracker URL in our Docker image documentation is not clickable
because the URL Markdown extracts automatically is broken.
Fix that and add some more links on how to get help and report issues.
Message-Id: <1471524880-2501-1-git-send-email-penberg@scylladb.com>
Fix Docker Hub documentation to match what we have right now.
More work is needed in the following areas:
* How to make a cluster
* How to configure Docker image for production use
