Here's /proc/meminfo:
MemTotal: 7629488 kB
MemFree: 237528 kB
Buffers: 70536 kB
Cached: 45612 kB
SwapCached: 0 kB
Active: 99400 kB
Inactive: 86340 kB
Active(anon): 69608 kB
Inactive(anon): 208 kB
Active(file): 29792 kB
Inactive(file): 86132 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 44 kB
Writeback: 0 kB
AnonPages: 69508 kB
Mapped: 7212 kB
Shmem: 224 kB
Slab: 7098800 kB
SReclaimable: 15452 kB
SUnreclaim: 7083348 kB
KernelStack: 1032 kB
PageTables: 4720 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 3814744 kB
Committed_AS: 176296 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 26116 kB
VmallocChunk: 34359710188 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 7872512 kB
DirectMap2M: 0 kB
free -m shows this:
total used free shared buffers cached
Mem: 7450 7219 231 0 69 44
-/+ buffers/cache: 7105 345
Swap: 0 0 0
Here's the first few lines of htop ordered by memory consumption:
1 [ 0.0%] Tasks: 75, 8 thr; 1 running
2 [| 0.7%] Load average: 0.08 0.03 0.05
Mem[|||||||||||||||||||||||||||||||||||||||||||||||||||7115/7450MB] Uptime: 1 day, 07:44:49
Swp[ 0/0MB]
PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command
983 redis 20 0 35324 26288 728 S 0.0 0.3 12:12.70 /usr/bin/redis-server /etc/redis/redis.conf
10152 bharadwaj 20 0 21760 4344 1760 S 0.0 0.1 0:00.21 bash -i
10923 bharadwaj 20 0 21748 4316 1748 S 0.0 0.1 0:00.24 bash -i
9931 bharadwaj 20 0 21704 4240 1716 S 0.0 0.1 0:00.14 bash -i
11278 bharadwaj 20 0 21704 4236 1712 S 0.0 0.1 0:00.14 bash -i
11689 bharadwaj 20 0 21704 4236 1712 S 0.0 0.1 0:00.13 bash -i
10917 bharadwaj 20 0 21704 4232 1712 S 0.0 0.1 0:00.20 bash -i
9873 bharadwaj 20 0 21704 4132 1612 S 0.0 0.1 0:00.14 -bash
10094 bharadwaj 20 0 21704 4128 1612 S 0.0 0.1 0:00.14 -bash
10744 bharadwaj 20 0 21704 4128 1612 S 0.0 0.1 0:00.24 -bash
10745 bharadwaj 20 0 21704 4128 1612 S 0.0 0.1 0:00.22 -bash
11220 bharadwaj 20 0 21704 4124 1612 S 0.0 0.1 0:00.14 -bash
11631 bharadwaj 20 0 21704 4124 1612 S 0.0 0.1 0:00.14 -bash
9997 root 20 0 73432 3648 2840 S 0.0 0.0 0:00.01 sshd: bharadwaj [priv]
10454 root 20 0 73432 3648 2840 S 0.0 0.0 0:00.01 sshd: bharadwaj [priv]
10452 root 20 0 73432 3644 2840 S 0.0 0.0 0:00.01 sshd: bharadwaj [priv]
11123 root 20 0 73432 3644 2840 S 0.0 0.0 0:00.01 sshd: bharadwaj [priv]
11490 root 20 0 73432 3644 2840 S 0.0 0.0 0:00.00 sshd: bharadwaj [priv]
9771 root 20 0 73432 3640 2840 S 0.0 0.0 0:00.01 sshd: bharadwaj [priv]
681 root 20 0 50036 2940 2332 S 0.0 0.0 0:02.37 /usr/sbin/sshd -D
11487 postfix 20 0 44308 2604 2040 S 0.0 0.0 0:00.00 smtp -t unix -u -c
11489 postfix 20 0 27416 2304 1780 S 0.0 0.0 0:00.00 local -t unix
Here's redis-cli INFO if that helps:
redis 127.0.0.1:6379> info
redis_version:2.2.12
redis_git_sha1:00000000
redis_git_dirty:0
arch_bits:64
multiplexing_api:epoll
process_id:983
uptime_in_seconds:113910
uptime_in_days:1
lru_clock:1825976
used_cpu_sys:186.84
used_cpu_user:545.43
used_cpu_sys_children:35.02
used_cpu_user_children:13.96
connected_clients:1
connected_slaves:0
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0
used_memory:23849056
used_memory_human:22.74M
used_memory_rss:26918912
mem_fragmentation_ratio:1.13
use_tcmalloc:0
loading:0
aof_enabled:0
changes_since_last_save:0
bgsave_in_progress:0
last_save_time:1423351594
bgrewriteaof_in_progress:0
total_connections_received:232605
total_commands_processed:20342906
expired_keys:6180
evicted_keys:0
keyspace_hits:19789182
keyspace_misses:276593
hash_max_zipmap_entries:512
hash_max_zipmap_value:64
pubsub_channels:0
pubsub_patterns:0
vm_enabled:0
role:master
db0:keys=4310,expires=79
There was a similar question asked before, but none of those answers helped the situation. Clearing cache or buffers didn't help as they consume something around 100 MB combined. Also, changing the redis maxmemory options with various values as given in their memory optimization page didn't help the situation. The server needs to be restarted every time memory-usage goes around 99%, which is when redis crashes.
How to fix the situation? I might be missing something basic. Any suggestions welcome!
EDIT: Here's the redis.conf file:
# Redis configuration file example
# Note on units: when memory size is needed, it is possible to specifiy
# it in the usual form of 1k 5GB 4M and so forth:
#
# 1k => 1000 bytes
# 1kb => 1024 bytes
# 1m => 1000000 bytes
# 1mb => 1024*1024 bytes
# 1g => 1000000000 bytes
# 1gb => 1024*1024*1024 bytes
#
# units are case insensitive so 1GB 1Gb 1gB are all the same.
# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes
# When running daemonized, Redis writes a pid file in /var/run/redis.pid by
# default. You can specify a custom pid file location here.
pidfile /var/run/redis/redis-server.pid
# Accept connections on the specified port, default is 6379.
# If port 0 is specified Redis will not listen on a TCP socket.
port 6379
# If you want you can bind a single interface, if the bind option is not
# specified all the interfaces will listen for incoming connections.
#
#bind 127.0.0.1
# Specify the path for the unix socket that will be used to listen for
# incoming connections. There is no default, so Redis will not listen
# on a unix socket when not specified.
#
# unixsocket /var/run/redis/redis.sock
# Close the connection after a client is idle for N seconds (0 to disable)
timeout 300
# Set server verbosity to 'debug'
# it can be one of:
# debug (a lot of information, useful for development/testing)
# verbose (many rarely useful info, but not a mess like the debug level)
# notice (moderately verbose, what you want in production probably)
# warning (only very important / critical messages are logged)
loglevel notice
# Specify the log file name. Also 'stdout' can be used to force
# Redis to log on the standard output. Note that if you use standard
# output for logging but daemonize, logs will be sent to /dev/null
logfile /var/log/redis/redis-server-2feb15.log
# To enable logging to the system logger, just set 'syslog-enabled' to yes,
# and optionally update the other syslog parameters to suit your needs.
# syslog-enabled no
# Specify the syslog identity.
# syslog-ident redis
# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
# syslog-facility local0
# Set the number of databases. The default database is DB 0, you can select
# a different one on a per-connection basis using SELECT <dbid> where
# dbid is a number between 0 and 'databases'-1
databases 16
################################ SNAPSHOTTING #################################
#
# Save the DB on disk:
#
# save <seconds> <changes>
#
# Will save the DB if both the given number of seconds and the given
# number of write operations against the DB occurred.
#
# In the example below the behaviour will be to save:
# after 900 sec (15 min) if at least 1 key changed
# after 300 sec (5 min) if at least 10 keys changed
# after 60 sec if at least 10000 keys changed
#
# Note: you can disable saving at all commenting all the "save" lines.
save 900 1
save 300 10
save 60 10000
# Compress string objects using LZF when dump .rdb databases?
# For default that's set to 'yes' as it's almost always a win.
# If you want to save some CPU in the saving child set it to 'no' but
# the dataset will likely be bigger if you have compressible values or keys.
rdbcompression yes
# The filename where to dump the DB
dbfilename dump.rdb
# The working directory.
#
# The DB will be written inside this directory, with the filename specified
# above using the 'dbfilename' configuration directive.
#
# Also the Append Only File will be created inside this directory.
#
# Note that you must specify a directory here, not a file name.
dir /var/lib/redis
################################# REPLICATION #################################
# Master-Slave replication. Use slaveof to make a Redis instance a copy of
# another Redis server. Note that the configuration is local to the slave
# so for example it is possible to configure the slave to save the DB with a
# different interval, or to listen to another port, and so on.
#
# slaveof <masterip> <masterport>
# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the slave to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the slave request.
#
# masterauth <master-password>
# When a slave lost the connection with the master, or when the replication
# is still in progress, the slave can act in two different ways:
#
# 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
# still reply to client requests, possibly with out of data data, or the
# data set may just be empty if this is the first synchronization.
#
# 2) if slave-serve-stale data is set to 'no' the slave will reply with
# an error "SYNC with master in progress" to all the kind of commands
# but to INFO and SLAVEOF.
#
slave-serve-stale-data yes
################################## SECURITY ###################################
# Require clients to issue AUTH <PASSWORD> before processing any other
# commands. This might be useful in environments in which you do not trust
# others with access to the host running redis-server.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# Warning: since Redis is pretty fast an outside user can try up to
# 150k passwords per second against a good box. This means that you should
# use a very strong password otherwise it will be very easy to break.
#
# requirepass foobared
# Command renaming.
#
# It is possilbe to change the name of dangerous commands in a shared
# environment. For instance the CONFIG command may be renamed into something
# of hard to guess so that it will be still available for internal-use
# tools but not available for general clients.
#
# Example:
#
# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
#
# It is also possilbe to completely kill a command renaming it into
# an empty string:
#
# rename-command CONFIG ""
################################### LIMITS ####################################
# Set the max number of connected clients at the same time. By default there
# is no limit, and it's up to the number of file descriptors the Redis process
# is able to open. The special value '0' means no limits.
# Once the limit is reached Redis will close all the new connections sending
# an error 'max number of clients reached'.
#
# maxclients 128
# Don't use more memory than the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys with an
# EXPIRE set. It will try to start freeing keys that are going to expire
# in little time and preserve keys with a longer time to live.
# Redis will also try to remove objects from free lists if possible.
#
# If all this fails, Redis will start to reply with errors to commands
# that will use more memory, like SET, LPUSH, and so on, and will continue
# to reply to most read-only commands like GET.
#
# WARNING: maxmemory can be a good idea mainly if you want to use Redis as a
# 'state' server or cache, not as a real DB. When Redis is used as a real
# database the memory usage will grow over the weeks, it will be obvious if
# it is going to use too much memory in the long run, and you'll have the time
# to upgrade. With maxmemory after the limit is reached you'll start to get
# errors for write operations, and this may even lead to DB inconsistency.
#
# maxmemory <bytes>
maxmemory 524288000
# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
# is reached? You can select among five behavior:
#
# volatile-lru -> remove the key with an expire set using an LRU algorithm
# allkeys-lru -> remove any key accordingly to the LRU algorithm
# volatile-random -> remove a random key with an expire set
# allkeys->random -> remove a random key, any key
# volatile-ttl -> remove the key with the nearest expire time (minor TTL)
# noeviction -> don't expire at all, just return an error on write operations
#
# Note: with all the kind of policies, Redis will return an error on write
# operations, when there are not suitable keys for eviction.
#
# At the date of writing this commands are: set setnx setex append
# incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
# sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
# zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
# getset mset msetnx exec sort
#
# The default is:
#
# maxmemory-policy volatile-lru
maxmemory-policy allkeys-lru
# LRU and minimal TTL algorithms are not precise algorithms but approximated
# algorithms (in order to save memory), so you can select as well the sample
# size to check. For instance for default Redis will check three keys and
# pick the one that was used less recently, you can change the sample size
# using the following configuration directive.
#
# maxmemory-samples 3
maxmemory-samples 3
############################## APPEND ONLY MODE ###############################
# By default Redis asynchronously dumps the dataset on disk. If you can live
# with the idea that the latest records will be lost if something like a crash
# happens this is the preferred way to run Redis. If instead you care a lot
# about your data and don't want to that a single record can get lost you should
# enable the append only mode: when this mode is enabled Redis will append
# every write operation received in the file appendonly.aof. This file will
# be read on startup in order to rebuild the full dataset in memory.
#
# Note that you can have both the async dumps and the append only file if you
# like (you have to comment the "save" statements above to disable the dumps).
# Still if append only mode is enabled Redis will load the data from the
# log file at startup ignoring the dump.rdb file.
#
# IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
# log file in background when it gets too big.
appendonly no
# The name of the append only file (default: "appendonly.aof")
# appendfilename appendonly.aof
# The fsync() call tells the Operating System to actually write data on disk
# instead to wait for more data in the output buffer. Some OS will really flush
# data on disk, some other OS will just try to do it ASAP.
#
# Redis supports three different modes:
#
# no: don't fsync, just let the OS flush the data when it wants. Faster.
# always: fsync after every write to the append only log . Slow, Safest.
# everysec: fsync only if one second passed since the last fsync. Compromise.
#
# The default is "everysec" that's usually the right compromise between
# speed and data safety. It's up to you to understand if you can relax this to
# "no" that will will let the operating system flush the output buffer when
# it wants, for better performances (but if you can live with the idea of
# some data loss consider the default persistence mode that's snapshotting),
# or on the contrary, use "always" that's very slow but a bit safer than
# everysec.
#
# If unsure, use "everysec".
# appendfsync always
appendfsync everysec
# appendfsync no
# When the AOF fsync policy is set to always or everysec, and a background
# saving process (a background save or AOF log background rewriting) is
# performing a lot of I/O against the disk, in some Linux configurations
# Redis may block too long on the fsync() call. Note that there is no fix for
# this currently, as even performing fsync in a different thread will block
# our synchronous write(2) call.
#
# In order to mitigate this problem it's possible to use the following option
# that will prevent fsync() from being called in the main process while a
# BGSAVE or BGREWRITEAOF is in progress.
#
# This means that while another child is saving the durability of Redis is
# the same as "appendfsync none", that in pratical terms means that it is
# possible to lost up to 30 seconds of log in the worst scenario (with the
# default Linux settings).
#
# If you have latency problems turn this to "yes". Otherwise leave it as
# "no" that is the safest pick from the point of view of durability.
no-appendfsync-on-rewrite no
################################ VIRTUAL MEMORY ###############################
# Virtual Memory allows Redis to work with datasets bigger than the actual
# amount of RAM needed to hold the whole dataset in memory.
# In order to do so very used keys are taken in memory while the other keys
# are swapped into a swap file, similarly to what operating systems do
# with memory pages.
#
# To enable VM just set 'vm-enabled' to yes, and set the following three
# VM parameters accordingly to your needs.
vm-enabled no
# vm-enabled yes
# This is the path of the Redis swap file. As you can guess, swap files
# can't be shared by different Redis instances, so make sure to use a swap
# file for every redis process you are running. Redis will complain if the
# swap file is already in use.
#
# The best kind of storage for the Redis swap file (that's accessed at random)
# is a Solid State Disk (SSD).
#
# *** WARNING *** if you are using a shared hosting the default of putting
# the swap file under /tmp is not secure. Create a dir with access granted
# only to Redis user and configure Redis to create the swap file there.
vm-swap-file /var/lib/redis/redis.swap
# vm-max-memory configures the VM to use at max the specified amount of
# RAM. Everything that deos not fit will be swapped on disk *if* possible, that
# is, if there is still enough contiguous space in the swap file.
#
# With vm-max-memory 0 the system will swap everything it can. Not a good
# default, just specify the max amount of RAM you can in bytes, but it's
# better to leave some margin. For instance specify an amount of RAM
# that's more or less between 60 and 80% of your free RAM.
vm-max-memory 0
# Redis swap files is split into pages. An object can be saved using multiple
# contiguous pages, but pages can't be shared between different objects.
# So if your page is too big, small objects swapped out on disk will waste
# a lot of space. If you page is too small, there is less space in the swap
# file (assuming you configured the same number of total swap file pages).
#
# If you use a lot of small objects, use a page size of 64 or 32 bytes.
# If you use a lot of big objects, use a bigger page size.
# If unsure, use the default :)
vm-page-size 32
# Number of total memory pages in the swap file.
# Given that the page table (a bitmap of free/used pages) is taken in memory,
# every 8 pages on disk will consume 1 byte of RAM.
#
# The total swap size is vm-page-size * vm-pages
#
# With the default of 32-bytes memory pages and 134217728 pages Redis will
# use a 4 GB swap file, that will use 16 MB of RAM for the page table.
#
# It's better to use the smallest acceptable value for your application,
# but the default is large in order to work in most conditions.
vm-pages 134217728
# Max number of VM I/O threads running at the same time.
# This threads are used to read/write data from/to swap file, since they
# also encode and decode objects from disk to memory or the reverse, a bigger
# number of threads can help with big objects even if they can't help with
# I/O itself as the physical device may not be able to couple with many
# reads/writes operations at the same time.
#
# The special value of 0 turn off threaded I/O and enables the blocking
# Virtual Memory implementation.
vm-max-threads 4
############################### ADVANCED CONFIG ###############################
# Hashes are encoded in a special way (much more memory efficient) when they
# have at max a given numer of elements, and the biggest element does not
# exceed a given threshold. You can configure this limits with the following
# configuration directives.
hash-max-zipmap-entries 512
hash-max-zipmap-value 64
# Similarly to hashes, small lists are also encoded in a special way in order
# to save a lot of space. The special representation is only used when
# you are under the following limits:
list-max-ziplist-entries 512
list-max-ziplist-value 64
# Sets have a special encoding in just one case: when a set is composed
# of just strings that happens to be integers in radix 10 in the range
# of 64 bit signed integers.
# The following configuration setting sets the limit in the size of the
# set in order to use this special memory saving encoding.
set-max-intset-entries 512
# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
# order to help rehashing the main Redis hash table (the one mapping top-level
# keys to values). The hash table implementation redis uses (see dict.c)
# performs a lazy rehashing: the more operation you run into an hash table
# that is rhashing, the more rehashing "steps" are performed, so if the
# server is idle the rehashing is never complete and some more memory is used
# by the hash table.
#
# The default is to use this millisecond 10 times every second in order to
# active rehashing the main dictionaries, freeing memory when possible.
#
# If unsure:
# use "activerehashing no" if you have hard latency requirements and it is
# not a good thing in your environment that Redis can reply form time to time
# to queries with 2 milliseconds delay.
#
# use "activerehashing yes" if you don't have such hard requirements but
# want to free memory asap when possible.
activerehashing yes
################################## INCLUDES ###################################
# Include one or more other config files here. This is useful if you
# have a standard template that goes to all redis server but also need
# to customize a few per-server settings. Include files can include
# other files, so use this wisely.
#
# include /path/to/local.conf
# include /path/to/other.conf
