- 16 Apr, 2014 1 commit
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antirez authored
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- 27 Mar, 2014 1 commit
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antirez authored
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- 25 Mar, 2014 13 commits
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antirez authored
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antirez authored
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antirez authored
In this commit: * Decrement steps are semantically differentiated from the reserved FDs. Previously both values were 32 but the meaning was different. * Make it clear that we save setrlimit errno. * Don't explicitly handle wrapping of 'f', but prevent it from happening. * Add comments to make the function flow more readable. This integrates PR #1630
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Matt Stancliff authored
errno may be reset by the previous call to redisLog, so capture the original value for proper error reporting.
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Matt Stancliff authored
Also update the original REDIS_EVENTLOOP_FDSET_INCR to include REDIS_MIN_RESERVED_FDS. REDIS_EVENTLOOP_FDSET_INCR exists to make sure more than (maxclients+RESERVED) entries are allocated, but we can only guarantee that if we include the current value of REDIS_MIN_RESERVED_FDS as a minimum for the INCR size.
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Matt Stancliff authored
Fun fact: rlim_t is an unsigned long long on all platforms. Continually subtracting from a rlim_t makes it get smaller and smaller until it wraps, then you're up to 2^64-1. This was causing an infinite loop on Redis startup if your ulimit was extremely (almost comically) low. The case of (f > oldlimit) would never be met in a case like: f = 150 while (f > 20) f -= 128 Since f is unsigned, it can't go negative and would take on values of: Iteration 1: 150 - 128 => 22 Iteration 2: 22 - 128 => 18446744073709551510 Iterations 3-∞: ... To catch the wraparound, we use the previous value of f stored in limit.rlimit_cur. If we subtract from f and get a larger number than the value it had previously, we print an error and exit since we don't have enough file descriptors to help the user at this point. Thanks to @bs3g for the inspiration to fix this problem. Patches existed from @bs3g at antirez#1227, but I needed to repair a few other parts of Redis simultaneously, so I didn't get a chance to use them.
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Matt Stancliff authored
The log messages about open file limits have always been slightly opaque and confusing. Here's an attempt to fix their wording, detail, and meaning. Users will have a better understanding of how to fix very common problems with these reworded messages. Also, we handle a new error case when maxclients becomes less than one, essentially rendering the server unusable. We now exit on startup instead of leaving the user with a server unable to handle any connections. This fixes antirez#356 as well.
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Matt Stancliff authored
32 was the additional number of file descriptors Redis would reserve when managing a too-low ulimit. The number 32 was in too many places statically, so now we use a macro instead that looks more appropriate. When Redis sets up the server event loop, it uses: server.maxclients+REDIS_EVENTLOOP_FDSET_INCR So, when reserving file descriptors, it makes sense to reserve at least REDIS_EVENTLOOP_FDSET_INCR FDs instead of only 32. Currently, REDIS_EVENTLOOP_FDSET_INCR is set to 128 in redis.h. Also, I replaced the static 128 in the while f < old loop with REDIS_EVENTLOOP_FDSET_INCR as well, which results in no change since it was already 128. Impact: Users now need at least maxclients+128 as their open file limit instead of maxclients+32 to obtain actual "maxclients" number of clients. Redis will carve the extra REDIS_EVENTLOOP_FDSET_INCR file descriptors it needs out of the "maxclients" range instead of failing to start (unless the local ulimit -n is too low to accomidate the request).
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Matt Stancliff authored
Everywhere in the Redis code base, maxclients is treated as an int with (int)maxclients or `maxclients = atoi(source)`, so let's make maxclients an int. This fixes a bug where someone could specify a negative maxclients on startup and it would work (as well as set maxclients very high) because: unsigned int maxclients; char *update = "-300"; maxclients = atoi(update); if (maxclients < 1) goto fail; But, (maxclients < 1) can only catch the case when maxclients is exactly 0. maxclients happily sets itself to -300, which isn't -300, but rather 4294966996, which isn't < 1, so... everything "worked." maxclients config parsing checks for the case of < 1, but maxclients CONFIG SET parsing was checking for case of < 0 (allowing maxclients to be set to 0). CONFIG SET parsing is now updated to match config parsing of < 1. It's tempting to add a MINIMUM_CLIENTS define, but... I didn't. These changes were inspired by antirez#356, but this doesn't fix that issue.
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Matt Stancliff authored
GCC-4.9 warned about this, but clang didn't. This commit fixes warning: sentinel.c: In function 'sentinelReceiveHelloMessages': sentinel.c:2156:43: warning: variable 'master' set but not used [-Wunused-but-set-variable] sentinelRedisInstance *ri = c->data, *master;
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antirez authored
In sentinelFlushConfig() fd could be undefined when the following if statement was true: if (rewrite_status == -1) goto werr; This could cause random file descriptors to get closed.
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Matt Stancliff authored
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Jan-Erik Rediger authored
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- 24 Mar, 2014 6 commits
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Matt Stancliff authored
Previously, the (!fp) would only catch lack of free space under OS X. Linux waits to discover it can't write until it actually writes contents to disk. (fwrite() returns success even if the underlying file has no free space to write into. All the errors only show up at flush/sync/close time.) Fixes antirez/redis#1604
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Jan-Erik Rediger authored
Includes changes from a dozen bug reports and pull requests. Was tested on Ubuntu, Debian and CentOS.
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antirez authored
Obtaining the RSS (Resident Set Size) info is slow in Linux and OSX. This slowed down the generation of the INFO 'memory' section. Since the RSS does not require to be a real-time measurement, we now sample it with server.hz frequency (10 times per second by default) and use this value both to show the INFO rss field and to compute the fragmentation ratio. Practically this does not make any difference for memory profiling of Redis but speeds up the INFO call significantly.
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antirez authored
For small content the function now tries to use a static buffer to avoid a malloc/free cycle that is too costly when the function is used in the context of performance critical code path such as INFO output generation. This change was verified to have positive effects in the execution speed of the INFO command.
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antirez authored
Uname was profiled to be a slow syscall. It produces always the same output in the context of a single execution of Redis, so calling it at every INFO output generation does not make too much sense. The uname utsname structure was modified as a static variable. At the same time a static integer was added to check if we need to call uname the first time.
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antirez authored
sdscatvprintf() uses a loop where it tries to output the formatted string in a buffer of the initial length, if there was not enough room, a buffer of doubled size is tried and so forth. The initial guess for the buffer length was very poor, an hardcoded "16". This caused the printf to be processed multiple times without a good reason. Given that printf functions are already not fast, the overhead was significant. The new heuristic is to use a buffer 4 times the length of the format buffer, and 32 as minimal size. This appears to be a good balance for typical uses of the function inside the Redis code base. This change improved INFO command performances 3 times.
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- 21 Mar, 2014 12 commits
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antirez authored
There were 2 spare bits inside the Redis object structure that are now used in order to enlarge 4x the range of the LRU field. At the same time the resolution was improved from 10 to 1 second: this still provides 194 days before the LRU counter overflows (restarting from zero). This is not a problem since it only causes lack of eviction precision for objects not touched for a very long time, and the lack of precision is only temporary.
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antirez authored
The padding field was totally useless: removed.
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antirez authored
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antirez authored
Now CONFIG RESETSTAT makes sure to reset all the fields, and in the future it will be simpler to avoid missing new fields.
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antirez authored
Test sentinel.tilt condition on top and return if it is true. This allows to remove the check for the tilt condition in the remaining code paths of the function.
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antirez authored
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antirez authored
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antirez authored
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antirez authored
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antirez authored
addReplySentinelRedisInstance() modified so that this field is displayed for all the kind of instances: Sentinels, Masters, Slaves.
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antirez authored
Failure detection in Sentinel is ping-pong based. It used to work by remembering the last time a valid PONG reply was received, and checking if the reception time was too old compared to the current current time. PINGs were sent at a fixed interval of 1 second. This works in a decent way, but does not scale well when we want to set very small values of "down-after-milliseconds" (this is the node timeout basically). This commit reiplements the failure detection making a number of changes. Some changes are inspired to Redis Cluster failure detection code: * A new last_ping_time field is added in representation of instances. If non zero, we have an active ping that was sent at the specified time. When a valid reply to ping is received, the field is zeroed again. * last_ping_time is not reset when we reconnect the link or send a new ping, so from our point of view it represents the time we started waiting for the instance to reply to our pings without receiving a reply. * last_ping_time is now used in order to check if the instance is timed out. This means that we can have a node timeout of 100 milliseconds and yet the system will work well since the new check is not bound to the period used to send pings. * Pings are now sent every second, or often if the value of down-after-milliseconds is less than one second. With a lower limit of 10 HZ ping frequency. * Link reconnection code was improved. This is used in order to try to reconnect the link when we are at 50% of the node timeout without a valid reply received yet. However the old code triggered unnecessary reconnections when the node timeout was very small. Now that should be ok. The new code passes the tests but more testing is needed and more unit tests stressing the failure detector, so currently this is merged only in the unstable branch.
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antirez authored
This makes debugging / monitoring of Sentinels simpler since you can identify sentinels in CLIENT LIST output of Redis instances.
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- 14 Mar, 2014 4 commits
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Matt Stancliff authored
argc == 2; argv[2] == crash
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antirez authored
Sentinel's main safety argument is that there are no two configurations for the same master with the same version (configuration epoch). For this to be true Sentinels require to be authorized by a majority. Additionally Sentinels require to do two important things: * Never vote again for the same epoch. * Never exchange an old vote for a fresh one. The first prerequisite, in a crash-recovery system model, requires to persist the master->leader_epoch on durable storage before to reply to messages. This was not the case. We also make sure to persist the current epoch in order to never reply to stale votes requests from other Sentinels, after a recovery. The configuration is persisted by making use of fsync(), this is considered in the context of this code a good enough guarantee that after a restart our durable state is restored, however this may not always be the case depending on the kind of hardware and operating system used.
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antirez authored
Now the way HELLO messages are received is unified. Now it is no longer needed for Sentinels to converge to the higher configuration for a master to be able to chat via some Redis instance, the are able to directly exchanges configurations. Note that this commit does not include the (trivial) change needed to send HELLO messages to Sentinel instances as well, since for an error I committed the change in the previous commit that refactored hello messages processing into a separated function.
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antirez authored
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- 13 Mar, 2014 1 commit
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antirez authored
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- 11 Mar, 2014 2 commits
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zhanghailei authored
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zhanghailei authored
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