As discussed in https://github.com/antirez/redis/issues/7364, it is good
to have a HELLO command variant, which does not switch the current proto
version of a redis server.
While `HELLO` will work, it introduced a certain difficulty on parsing
options of the command. We will need to offset the index of authentication
and setname option by -1.
So 0 is marked a special version meaning non-switching. And we do not
need to change the code much.
As discussed in https://github.com/antirez/redis/issues/7364, it is good
to have a HELLO command variant, which does not switch the current proto
version of a redis server.
While `HELLO` will work, it introduced a certain difficulty on parsing
options of the command. We will need to offset the index of authentication
and setname option by -1.
So 0 is marked a special version meaning non-switching. And we do not
need to change the code much.
Apparently the "leaks" took reports a different error string about process
that's not found in each version of MacOS.
This cause the test suite to fail on some OS versions, since some tests terminate
the process before looking for leaks.
Instead of looking at the error string, we now look at the (documented) exit code.
Apparently the "leaks" took reports a different error string about process
that's not found in each version of MacOS.
This cause the test suite to fail on some OS versions, since some tests terminate
the process before looking for leaks.
Instead of looking at the error string, we now look at the (documented) exit code.
When a database on a 64 bit build grows past 2^31 keys, the underlying hash table expands to 2^32 buckets. After this point, the algorithms for selecting random elements only return elements from half of the available buckets because they use random() which has a range of 0 to 2^31 - 1. This causes problems for eviction policies which use dictGetSomeKeys or dictGetRandomKey. Over time they cause the hash table to become unbalanced because, while new keys are spread out evenly across all buckets, evictions come from only half of the available buckets. Eventually this half of the table starts to run out of keys and it takes longer and longer to find candidates for eviction. This continues until no more evictions can happen.
This solution addresses this by using a 64 bit PRNG instead of libc random().
Co-authored-by: Greg Femec <gfemec@google.com>
When a database on a 64 bit build grows past 2^31 keys, the underlying hash table expands to 2^32 buckets. After this point, the algorithms for selecting random elements only return elements from half of the available buckets because they use random() which has a range of 0 to 2^31 - 1. This causes problems for eviction policies which use dictGetSomeKeys or dictGetRandomKey. Over time they cause the hash table to become unbalanced because, while new keys are spread out evenly across all buckets, evictions come from only half of the available buckets. Eventually this half of the table starts to run out of keys and it takes longer and longer to find candidates for eviction. This continues until no more evictions can happen.
This solution addresses this by using a 64 bit PRNG instead of libc random().
Co-authored-by: Greg Femec <gfemec@google.com>
Turns out that when the fork child crashes, the crash log was deleting
the pidfile from the disk (although the parent is still running.
Now we set the pidfile of the fork process to NULL so the fork process
will never deletes it.
Turns out that when the fork child crashes, the crash log was deleting
the pidfile from the disk (although the parent is still running.
Now we set the pidfile of the fork process to NULL so the fork process
will never deletes it.
Normally IO threads should simply read data from the socket into the
buffer and attempt to parse it.
If a protocol error is detected, a reply is generated which may result
with installing a write handler which is not thread safe. This fix
delays that until the client is processed back in the main thread.
Fixes#8220
Normally IO threads should simply read data from the socket into the
buffer and attempt to parse it.
If a protocol error is detected, a reply is generated which may result
with installing a write handler which is not thread safe. This fix
delays that until the client is processed back in the main thread.
Fixes#8220
In the distant history there was only the read flag for commands, and whatever
command that didn't have the read flag was a write one.
Then we added the write flag, but some portions of the code still used !read
Also some commands that don't work on the keyspace at all, still have the read
flag.
Changes in this commit:
1. remove the read-only flag from TIME, ECHO, ROLE and LASTSAVE
2. EXEC command used to decides if it should propagate a MULTI by looking at
the command flags (!read & !admin).
When i was about to change it to look at the write flag instead, i realized
that this would cause it not to propagate a MULTI for PUBLISH, EVAL, and
SCRIPT, all 3 are not marked as either a read command or a write one (as
they should), but all 3 are calling forceCommandPropagation.
So instead of introducing a new flag to denote a command that "writes" but
not into the keyspace, and still needs propagation, i decided to rely on
the forceCommandPropagation, and just fix the code to propagate MULTI when
needed rather than depending on the command flags at all.
The implication of my change then is that now it won't decide to propagate
MULTI when it sees one of these: SELECT, PING, INFO, COMMAND, TIME and
other commands which are neither read nor write.
3. Changing getNodeByQuery and clusterRedirectBlockedClientIfNeeded in
cluster.c to look at !write rather than read flag.
This should have no implications, since these code paths are only reachable
for commands which access keys, and these are always marked as either read
or write.
This commit improve MULTI propagation tests, for modules and a bunch of
other special cases, all of which used to pass already before that commit.
the only one that test change that uncovered a change of behavior is the
one that DELs a non-existing key, it used to propagate an empty
multi-exec block, and no longer does.
In the distant history there was only the read flag for commands, and whatever
command that didn't have the read flag was a write one.
Then we added the write flag, but some portions of the code still used !read
Also some commands that don't work on the keyspace at all, still have the read
flag.
Changes in this commit:
1. remove the read-only flag from TIME, ECHO, ROLE and LASTSAVE
2. EXEC command used to decides if it should propagate a MULTI by looking at
the command flags (!read & !admin).
When i was about to change it to look at the write flag instead, i realized
that this would cause it not to propagate a MULTI for PUBLISH, EVAL, and
SCRIPT, all 3 are not marked as either a read command or a write one (as
they should), but all 3 are calling forceCommandPropagation.
So instead of introducing a new flag to denote a command that "writes" but
not into the keyspace, and still needs propagation, i decided to rely on
the forceCommandPropagation, and just fix the code to propagate MULTI when
needed rather than depending on the command flags at all.
The implication of my change then is that now it won't decide to propagate
MULTI when it sees one of these: SELECT, PING, INFO, COMMAND, TIME and
other commands which are neither read nor write.
3. Changing getNodeByQuery and clusterRedirectBlockedClientIfNeeded in
cluster.c to look at !write rather than read flag.
This should have no implications, since these code paths are only reachable
for commands which access keys, and these are always marked as either read
or write.
This commit improve MULTI propagation tests, for modules and a bunch of
other special cases, all of which used to pass already before that commit.
the only one that test change that uncovered a change of behavior is the
one that DELs a non-existing key, it used to propagate an empty
multi-exec block, and no longer does.
In response to large client query buffer optimization introduced in 1898e6c. The calculation of the amount of
remaining bytes we need to write to the query buffer was calculated wrong, as a result we are unnecessarily
growing the client query buffer by sdslen(c->querybuf) always. This fix corrects that behavior.
Please note the previous behavior prior to the before-mentioned change was correctly calculating the remaining
additional bytes, and this change makes that calculate to be consistent.
Useful context, the argument of size `ll` starts at qb_pos (which is now the beginning of the sds), but much of it
may have already been read from the socket, so we only need to grow the sds for the remainder of it.
In response to large client query buffer optimization introduced in 1898e6c. The calculation of the amount of
remaining bytes we need to write to the query buffer was calculated wrong, as a result we are unnecessarily
growing the client query buffer by sdslen(c->querybuf) always. This fix corrects that behavior.
Please note the previous behavior prior to the before-mentioned change was correctly calculating the remaining
additional bytes, and this change makes that calculate to be consistent.
Useful context, the argument of size `ll` starts at qb_pos (which is now the beginning of the sds), but much of it
may have already been read from the socket, so we only need to grow the sds for the remainder of it.
