- 24 May, 2012 1 commit
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antirez authored
During the AOF rewrite process, the parent process needs to accumulate the new writes in an in-memory buffer: when the child will terminate the AOF rewriting process this buffer (that ist the difference between the dataset when the rewrite was started, and the current dataset) is flushed to the new AOF file. We used to implement this buffer using an sds.c string, but sds.c has a 2GB limit. Sometimes the dataset can be big enough, the amount of writes so high, and the rewrite process slow enough that we overflow the 2GB limit, causing a crash, documented on github by issue #504. In order to prevent this from happening, this commit introduces a new system to accumulate writes, implemented by a linked list of blocks of 10 MB each, so that we also avoid paying the reallocation cost. Note that theoretically modern operating systems may implement realloc() simply as a remaping of the old pages, thus with very good performances, see for instance the mremap() syscall on Linux. However this is not always true, and jemalloc by default avoids doing this because there are issues with the current implementation of mremap(). For this reason we are using a linked list of blocks instead of a single block that gets reallocated again and again. The changes in this commit lacks testing, that will be performed before merging into the unstable branch. This fix will not enter 2.4 because it is too invasive. However 2.4 will log a warning when the AOF rewrite buffer is near to the 2GB limit.
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- 14 May, 2012 3 commits
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antirez authored
activeExpireCycle() can consume no more than a few milliseconds per iteration. This commit improves the precision of the check for the time elapsed in two ways: 1) We check every 16 iterations instead of the main loop instead of 256. 2) We reset iterations at the start of the function and not every time we switch to the next database, so the check is correctly performed every 16 iterations.
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antirez authored
A previous commit introduced REDIS_HZ define that changes the frequency of calls to the serverCron() Redis function. This commit improves different related things: 1) Software watchdog: now the minimal period can be set according to REDIS_HZ. The minimal period is two times the timer period, that is: (1000/REDIS_HZ)*2 milliseconds 2) The incremental rehashing is now performed in the expires dictionary as well. 3) The activeExpireCycle() function was improved in different ways: - Now it checks if it already used too much time using microseconds instead of milliseconds for better precision. - The time limit is now calculated correctly, in the previous version the division was performed before of the multiplication resulting in a timelimit of 0 if HZ was big enough. - Databases with less than 1% of buckets fill in the hash table are skipped, because getting random keys is too expensive in this condition. 4) tryResizeHashTables() is now called at every timer call, we need to match the number of calls we do to the expired keys colleciton cycle. 5) REDIS_HZ was raised to 100.
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antirez authored
Redis uses a function called serverCron() that is very similar to the timer interrupt of an operating system. This function is used to handle a number of asynchronous things, like active expired keys collection, clients timeouts, update of statistics, things related to the cluster and replication, triggering of BGSAVE and AOF rewrite process, and so forth. In the past the timer was called 1 time per second. At some point it was raised to 10 times per second, but it still was fixed and could not be changed even at compile time, because different functions called from serverCron() assumed a given fixed frequency. This commmit makes the frequency configurable, so that it is simpler to pick a good tradeoff between overhead of this function (that is usually very small) and the responsiveness of Redis during a few critical circumstances where a lot of work is done inside the timer. An example of such a critical condition is mass-expire of a lot of keys in the same second. Up to a given percentage of CPU time is used to perform expired keys collection per expire cylce. Now changing the REDIS_HZ macro it is possible to do less work but more times per second in order to block the server for less time. If this patch will work well in our tests it will enter Redis 2.6-final.
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- 12 May, 2012 2 commits
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antirez authored
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antirez authored
If a large amonut of keys are all expiring about at the same time, the "active" expired keys collection cycle used to block as far as the percentage of already expired keys was >= 25% of the total population of keys with an expire set. This could block the server even for many seconds in order to reclaim memory ASAP. The new algorithm uses at max a small amount of milliseconds per cycle, even if this means reclaiming the memory less promptly it also means a more responsive server.
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- 02 May, 2012 1 commit
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antirez authored
We used to reply -ERR ... message ..., now the reply is instead -MASTERDOWN ... message ... so that it can be distinguished easily by the other error conditions.
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- 27 Apr, 2012 1 commit
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antirez authored
This commit reverts most of c5757662, in order to use back main stack for signal handling. The main reason is that otherwise it is completely pointless that we do a lot of efforts to print the stack trace on crash, and the content of the stack and registers as well. Using an alternate stack broken this feature completely.
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- 19 Apr, 2012 1 commit
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antirez authored
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- 18 Apr, 2012 1 commit
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antirez authored
1) Don't accept maxclients set to < 0 2) Allow maxclients < 1024, it is useful for testing.
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- 13 Apr, 2012 3 commits
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antirez authored
After considering the interaction between ability to delcare globals in scripts using the 'global' function, and the complexities related to hanlding replication and AOF in a sane way with globals AND ability to turn protection On and Off, we reconsidered the design. The new design makes clear that there is only one good way to write Redis scripts, that is not using globals. In the rare cases state must be retained across calls a Redis key can be used.
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antirez authored
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antirez authored
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- 10 Apr, 2012 2 commits
- 08 Apr, 2012 1 commit
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antirez authored
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- 06 Apr, 2012 1 commit
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antirez authored
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- 05 Apr, 2012 1 commit
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Premysl Hruby authored
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- 04 Apr, 2012 4 commits
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antirez authored
Structure field controlling the INFO field master_link_down_since_seconds initialized correctly to avoid strange INFO output at startup when a slave has yet to connect to its master.
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antirez authored
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antirez authored
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antirez authored
Print milliseconds of the current second in log lines timestamps. Sometimes precise timing is very important for debugging.
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- 03 Apr, 2012 1 commit
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antirez authored
When the user-provided 'maxclients' value is too big for the max number of files we can open, at least try to search the max the OS is allowing (in steps of 256 filedes).
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- 30 Mar, 2012 1 commit
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Joseph Jang authored
occurs when two or more dbs are replicated and at least one of them is >db10
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- 28 Mar, 2012 3 commits
- 27 Mar, 2012 1 commit
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Premysl Hruby authored
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- 25 Mar, 2012 1 commit
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antirez authored
This new field counts all the times Redis is configured with AOF enabled and fsync policy 'everysec', but the previous fsync performed by the background thread was not able to complete within two seconds, forcing Redis to perform a write against the AOF file while the fsync is still in progress (likely a blocking operation).
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- 24 Mar, 2012 1 commit
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antirez authored
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- 22 Mar, 2012 3 commits
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antirez authored
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antirez authored
DEBUG should not be flagged as w otherwise we can not call DEBUG DIGEST and other commands against read only slaves.
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antirez authored
This commit introduces support for read only slaves via redis.conf and CONFIG GET/SET commands. Also various semantical fixes are implemented here: 1) MULTI/EXEC with only read commands now work where the server is into a state where writes (or commands increasing memory usage) are not allowed. Before this patch everything inside a transaction would fail in this conditions. 2) Scripts just calling read-only commands will work against read only slaves, when the server is out of memory, or when persistence is into an error condition. Before the patch EVAL always failed in this condition.
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- 19 Mar, 2012 1 commit
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antirez authored
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- 18 Mar, 2012 3 commits
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antirez authored
More memory tests implemented. Default number of iterations lowered to a more acceptable value of 50.
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antirez authored
Number of iteration of --test-memory is now 300 (several minutes per gigabyte). Memtest86 and Memtester links are also displayed while running the test.
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antirez authored
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- 15 Mar, 2012 1 commit
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antirez authored
Use a simple protocol between clientsCron() and helper functions to understand if the client is still valind and clientsCron() should continue processing or if the client was freed and we should continue with the next one.
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- 14 Mar, 2012 2 commits