3eb8314be6
Instead of a dictEntry with pointers to key and value, the hashtable
has a pointer directly to the value (robj) which can hold an embedded
key and acts as a key-value in the hashtable. This minimizes the number
of pointers to follow and thus the number of memory accesses to lookup
a key-value pair.
Keys robj
hashtable
+-------+ +-----------------------+
| 0 | | type, encoding, LRU |
| 1 ------->| refcount, expire |
| 2 | | ptr |
| ... | | optional embedded key |
+-------+ | optional embedded val |
+-----------------------+
The expire timestamp (TTL) is also stored in the robj, if any. The expire
hash table points to the same robj.
Overview of changes:
* Replace dict with hashtable in kvstore (kvstore.c)
* Add functions for embedding key and expire in robj (object.c)
* When there's unused space, reserve an expire field to avoid realloting
it later if expire is added.
* Always reserve space for expire for large key names to avoid realloc
if it's set later.
* Update db functions (db.c)
* dbAdd, setKey and setExpire reallocate the object when embedding a key
* setKey does not increment the reference counter, since it would require
duplicating the object. This responsibility is moved to the caller.
* Remove logic for shared integer objects as values in the database. The keys
are now embedded in the objects, so all objects in the database need to be
unique. Thus, we can't use shared objects as values. Also delete test cases
for shared integers.
* Adjust various commands to the changes mentioned above.
* Adjust defrag code
* Improvement: Don't access the expires table before defrag has actually
reallocated the object.
* Adjust test cases that were using hard-coded sizes for dict when realloc
would happen, and some other adjustments in test cases.
* Adjust memory prefetch for new hash table implementation in IO-threading,
using new `hashtableIncrementalFind` API
* Adjust offloading of free() to IO threads: Object free to be done in main
thread while keeping obj->ptr offloading in IO-thread since the DB object is
now allocated by the main-thread and not by the IO-thread as it used to be.
* Let expireIfNeeded take an optional value, to avoid looking up the expires
table when possible.
---------
Signed-off-by: Uri Yagelnik <uriy@amazon.com>
Signed-off-by: uriyage <78144248+uriyage@users.noreply.github.com>
Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
Co-authored-by: Uri Yagelnik <uriy@amazon.com>
Valkey Test Suite
Overview
Integration tests are written in Tcl, a high-level, general-purpose, interpreted, dynamic programming language [source].
runtest is the main entrance point for running integration tests.
For example, to run a single test;
./runtest --single unit/your_test_name
# For additional arguments, you may refer to the `runtest` script itself.
The normal execution mode of the test suite involves starting and manipulating
local valkey-server instances, inspecting process state, log files, etc.
The test suite also supports execution against an external server, which is
enabled using the --host and --port parameters. When executing against an
external server, tests tagged external:skip are skipped.
There are additional runtime options that can further adjust the test suite to
match different external server configurations. All options are listed by
./runtest --help. The following table is just a subset of the options:
| Option | Impact |
|---|---|
--singledb |
Only use database 0, don't assume others are supported. |
--ignore-encoding |
Skip all checks for specific encoding. |
--ignore-digest |
Skip key value digest validations. |
--cluster-mode |
Run in strict Valkey Cluster compatibility mode. |
--large-memory |
Enables tests that consume more than 100MB |
--tls |
Run tests with TLS. See below. |
--tls-module |
Run tests with TLS, when TLS support is built as a module. |
--help |
Displays the full set of options. |
Running with TLS requires the following preparations:
- Build Valkey is TLS support, e.g. using
make BUILD_TLS=yes, ormake BUILD_TLS=module. - Run
./utils/gen-test-certs.shto generate a root CA and a server certificate. - Install TLS support for TCL, e.g. the
tcl-tlspackage on Debian/Ubuntu.
Additional tests
Not all tests are included in the ./runtest scripts. Some additional entry points are provided by the following scripts, which support a subset of the options listed above:
./runtest-clusterruns more extensive tests for Valkey Cluster. Some cluster tests are included in./runtest, but not all../runtest-sentinelruns tests of Valkey Sentinel../runtests-moduleruns tests of the module API.
Debugging
You can set a breakpoint and invoke a minimal debugger using the bp function.
... your test code before break-point
bp 1
... your test code after break-point
The bp 1 will give back the tcl interpreter to the developer, and allow you to interactively print local variables (through puts), run functions and so forth [source].
bp takes a single argument, which is 1 for the case above, and is used to label a breakpoint with a string.
Labels are printed out when breakpoints are hit, so you can identify which breakpoint was triggered.
Breakpoints can be skipped by setting the global variable ::bp_skip, and by providing the labels you want to skip.
The minimal debugger comes with the following predefined functions.
- Press
cto continue past the breakpoint. - Press
ito print local variables.
Tags
Tags are applied to tests to classify them according to the subsystem they test, but also to indicate compatibility with different run modes and required capabilities.
Tags can be applied in different context levels:
start_servercontexttagscontext that bundles several tests together- A single test context.
The following compatibility and capability tags are currently used:
| Tag | Indicates |
|---|---|
external:skip |
Not compatible with external servers. |
cluster:skip |
Not compatible with --cluster-mode. |
large-memory |
Test that requires more than 100MB |
tls:skip |
Not compatible with --tls. |
needs:repl |
Uses replication and needs to be able to SYNC from server. |
needs:debug |
Uses the DEBUG command or other debugging focused commands (like OBJECT REFCOUNT). |
needs:pfdebug |
Uses the PFDEBUG command. |
needs:config-maxmemory |
Uses CONFIG SET to manipulate memory limit, eviction policies, etc. |
needs:config-resetstat |
Uses CONFIG RESETSTAT to reset statistics. |
needs:reset |
Uses RESET to reset client connections. |
needs:save |
Uses SAVE or BGSAVE to create an RDB file. |
When using an external server (--host and --port), filtering using the
external:skip tags is done automatically.
When using --cluster-mode, filtering using the cluster:skip tag is done
automatically.
When not using --large-memory, filtering using the largemem:skip tag is done
automatically.
In addition, it is possible to specify additional configuration. For example, to
run tests on a server that does not permit SYNC use:
./runtest --host <host> --port <port> --tags -needs:repl