In docs/alternator/compatibility.md we said that although Alternator
supports authentication, it doesn't support authorization (access
control). Now it does, so the relevant text needs to be corrected
to fit what we have today.
It's still in the compatibility.md document because it's not the same
API as DynamoDB's, so users with existing applications may need to be
aware of this difference.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Update several aspects of the alternator/getting-started.md which were
not up-to-date:
* When the documented was written, Alternator was moving quickly so we
recommended running a nightly version. This is no longer the case, so
we should recommend running the latest stable build.
* The link to the download link is no longer helpful for getting Docker
instructions (it shows some generic download options). Instead point to
our dockerhub page.
* Replace mentions of "Scylla" by the new official name, "ScyllaDB".
* Miscelleneous copy-edits.
Fixes#11218
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#11605
Drop the adjective "experimental" used to describe Alternator in
docs/alternator/getting-started.md.
In Scylla, the word "experimental" carries a specific meaning - no support
for upgrades, not enough QA, not ready for general use) and Alternator is
no longer experimental in that sense.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20201112185249.941484-1-nyh@scylladb.com>
alternator/getting-started.md had a missing grave accent (`) character,
resulting in messed up rendering of the involved paragraph. Add the missing
quote.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200827110920.187328-1-nyh@scylladb.com>
We already have a docker image option to enable alternator on an unencrypted
port, "--alternator-port", but we forgot to also allow the similar option
for enabling alternator on an encrypted (HTTPS) port: "--alternator-https-port"
so this patch adds the missing option, and documents how to use it.
Note that using this option is not enough. When this option is used,
Alternator also requires two files, /etc/scylla/scylla.crt and
/etc/scylla/scylla.key, to be inserted into the image. These files should
contain the SSL certificate, and key, respectively. If these files are
missing, you will get an error in the log about the missing file.
Fixes#6583.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200621125219.12274-1-nyh@scylladb.com>
Alternator supports four ways in which write operations can use quorum
writes or LWT or both, which we called "write isolation policies".
Until this patch, Alternator defaulted to the most generally safe policy,
"always_use_lwt". This default could have been overriden for each table
separately, but there was no way to change this default for all tables.
This patch adds a "--alternator-write-isolation" configuration option which
allows changing the default.
Moreover, @dorlaor asked that users must *explicitly* choose this default
mode, and not get "always_use_lwt" without noticing. The previous default,
"always_use_lwt" supports any workload correctly but because it uses LWT
for all writes it may be disappointingly slow for users who run write-only
workloads (including most benchmarks) - such users might find the slow
writes so disappointing that they will drop Scylla. Conversely, a default
of "forbid_rmw" will be faster and still correct, but will fail on workloads
which need read-modify-write operations - and suprise users that need these
operations. So Dor asked that that *none* of the write modes be made the
default, and users must make an informed choice between the different write
modes, rather than being disappointed by a default choice they weren't
aware of.
So after this patch, Scylla refuses to boot if Alternator is enabled but
a "--alternator-write-isolation" option is missing.
The patch also modifies the relevant documentation, adds the same option to
our docker image, and the modifies the test-running script
test/alternator/run to run Scylla with the old default mode (always_use_lwt),
which we need because we want to test RMW operations as well.
Fixes#6452
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200524160338.108417-1-nyh@scylladb.com>
Since commit 9948f548a5, the LWT no longer
requires an "experimental" flag, so Alternator documents and scripts
which referred to the need for enabling experimental LWT, are fixed here
to no longer do that.
Fixes#6118.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200405143237.12693-1-nyh@scylladb.com>
The instructions in docs/alternator/getting-started.md on how to run
Alternator with docker are outdated and confusing, so this patch updates
them.
First, the instructions recommended the scylladb/scylla-nightly:alternator
tag, but we only ever created this tag once, and never updated it. Since
then, Alternator has been constantly improving, and we've caught up on
a lot of features, and people who want to test or evaluate Alternator
will most likely want to run the latest nightly build, with all the latest
Alternator features. So we update the instructions to request the latest
nightly build - and mention the need to explictly do "docker pull" (without
this step, you can find yourself running an antique nightly build, which
you downloaded months ago!). This instruction can be revisited once
Alternator is GAed and not improving quickly and we can then recommend to
run the latest stable Scylla - but I think we're not there yet.
Second, in recent builds, Alternator requires that the LWT feature is
enabled, and since LWT is still experimental, this means that one needs
to add "--experimental 1" to the "docker run" command. Without it, the
command line in getting-started.md will refuse to boot, complaining that
Alternator was enabled but LWT wasn't. So this patch adds the
"--experimental 1" in the relevant places in the text. Again, this
instruction can and should be revisited once LWT goes out of experimental
mode.
Fixes#5813
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200216113601.9535-1-nyh@scylladb.com>
The example Python code had wrong indentation, and wouldn't actually
work if naively copy-pasted. Noticed by Noam Hasson.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20190929091440.28042-1-nyh@scylladb.com>
This patch adds a getting started document for alternator,
it explains how to start up a cluster that has an alternator
API port open and how to test that it works using either an
application or some simple and minimal python scripts.
The goal of the document is to get a user to have an up and
running docker based cluster with alternator support in the
shortest time possible.
