title: Redis server not starting
body: <p>Hi I have problem with redis,</p>
  
  <p>when i try to start the server, I get an error:</p>
  
  <p><strong>* FATAL CONFIG FILE ERROR *</strong>
  Reading the configuration file, at line 56</p>
  
  <blockquote>
    <blockquote>
      <blockquote>
        <p>'tcp-keepalive 0'
        Bad directive or wrong number of arguments</p>
      </blockquote>
    </blockquote>
  </blockquote>
  
  <p>Content of the configuation file is give below:</p>
  
  <h1>Redis configuration file example</h1>
  
  <pre><code># Note on units: when memory size is needed, it is possible to specify
  # it in the usual form of 1k 5GB 4M and so forth:
  #
  # 1k =&gt; 1000 bytes
  # 1kb =&gt; 1024 bytes
  # 1m =&gt; 1000000 bytes
  # 1mb =&gt; 1024*1024 bytes
  # 1g =&gt; 1000000000 bytes
  # 1gb =&gt; 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 no
  
  # 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.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 /tmp/redis.sock
  # unixsocketperm 755
  
  # Close the connection after a client is idle for N seconds (0 to disable)
  timeout 0
  
  # TCP keepalive.
  #
  # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
  # of communication. This is useful for two reasons:
  #
  # 1) Detect dead peers.
  # 2) Take the connection alive from the point of view of network
  #    equipment in the middle.
  #
  # On Linux, the specified value (in seconds) is the period used to send ACKs.
  # Note that to close the connection the double of the time is needed.
  # On other kernels the period depends on the kernel configuration.
  #
  # A reasonable value for this option is 60 seconds.
  tcp-keepalive 0
  
  # Specify the server verbosity level.
  # This 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 stdout
  
  # 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 &lt;dbid&gt; where
  # dbid is a number between 0 and 'databases'-1
  databases 16
  
  ################################ SNAPSHOTTING  #################################
  #
  # Save the DB on disk:
  #
  #   save &lt;seconds&gt; &lt;changes&gt;
  #
  #   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.
  #
  #   It is also possible to remove all the previously configured save
  #   points by adding a save directive with a single empty string argument
  #   like in the following example:
  #
  #   save ""
  
  save 900 1
  save 300 10
  save 60 10000
  
  # By default Redis will stop accepting writes if RDB snapshots are enabled
  # (at least one save point) and the latest background save failed.
  # This will make the user aware (in an hard way) that data is not persisting
  # on disk properly, otherwise chances are that no one will notice and some
  # distater will happen.
  #
  # If the background saving process will start working again Redis will
  # automatically allow writes again.
  #
  # However if you have setup your proper monitoring of the Redis server
  # and persistence, you may want to disable this feature so that Redis will
  # continue to work as usually even if there are problems with disk,
  # permissions, and so forth.
  stop-writes-on-bgsave-error yes
  
  # 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
  
  # Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
  # This makes the format more resistant to corruption but there is a performance
  # hit to pay (around 10%) when saving and loading RDB files, so you can disable it
  # for maximum performances.
  #
  # RDB files created with checksum disabled have a checksum of zero that will
  # tell the loading code to skip the check.
  rdbchecksum 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.
  # 
  # The Append Only File will also be created inside this directory.
  # 
  # Note that you must specify a directory here, not a file name.
  dir ./
  
  ################################# 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 &lt;masterip&gt; &lt;masterport&gt;
  
  # 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 &lt;master-password&gt;
  
  # When a slave loses its 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 date 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
  
  # You can configure a slave instance to accept writes or not. Writing against
  # a slave instance may be useful to store some ephemeral data (because data
  # written on a slave will be easily deleted after resync with the master) but
  # may also cause problems if clients are writing to it because of a
  # misconfiguration.
  #
  # Since Redis 2.6 by default slaves are read-only.
  #
  # Note: read only slaves are not designed to be exposed to untrusted clients
  # on the internet. It's just a protection layer against misuse of the instance.
  # Still a read only slave exports by default all the administrative commands
  # such as CONFIG, DEBUG, and so forth. To a limited extend you can improve
  # security of read only slaves using 'rename-command' to shadow all the
  # administrative / dangerous commands.
  slave-read-only yes
  
  # Slaves send PINGs to server in a predefined interval. It's possible to change
  # this interval with the repl_ping_slave_period option. The default value is 10
  # seconds.
  #
  # repl-ping-slave-period 10
  
  # The following option sets a timeout for both Bulk transfer I/O timeout and
  # master data or ping response timeout. The default value is 60 seconds.
  #
  # It is important to make sure that this value is greater than the value
  # specified for repl-ping-slave-period otherwise a timeout will be detected
  # every time there is low traffic between the master and the slave.
  #
  # repl-timeout 60
  
  # Disable TCP_NODELAY on the slave socket after SYNC?
  #
  # If you select "yes" Redis will use a smaller number of TCP packets and
  # less bandwidth to send data to slaves. But this can add a delay for
  # the data to appear on the slave side, up to 40 milliseconds with
  # Linux kernels using a default configuration.
  #
  # If you select "no" the delay for data to appear on the slave side will
  # be reduced but more bandwidth will be used for replication.
  #
  # By default we optimize for low latency, but in very high traffic conditions
  # or when the master and slaves are many hops away, turning this to "yes" may
  # be a good idea.
  repl-disable-tcp-nodelay no
  
  # The slave priority is an integer number published by Redis in the INFO output.
  # It is used by Redis Sentinel in order to select a slave to promote into a
  # master if the master is no longer working correctly.
  #
  # A slave with a low priority number is considered better for promotion, so
  # for instance if there are three slaves with priority 10, 100, 25 Sentinel will
  # pick the one wtih priority 10, that is the lowest.
  #
  # However a special priority of 0 marks the slave as not able to perform the
  # role of master, so a slave with priority of 0 will never be selected by
  # Redis Sentinel for promotion.
  #
  # By default the priority is 100.
  slave-priority 100
  
  ################################## SECURITY ###################################
  
  # Require clients to issue AUTH &lt;PASSWORD&gt; 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 possible to change the name of dangerous commands in a shared
  # environment. For instance the CONFIG command may be renamed into something
  # hard to guess so that it will still be available for internal-use tools
  # but not available for general clients.
  #
  # Example:
  #
  # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
  #
  # It is also possible to completely kill a command by renaming it into
  # an empty string:
  #
  # rename-command CONFIG ""
  #
  # Please note that changing the name of commands that are logged into the
  # AOF file or transmitted to slaves may cause problems.
  
  ################################### LIMITS ####################################
  
  # Set the max number of connected clients at the same time. By default
  # this limit is set to 10000 clients, however if the Redis server is not
  # able to configure the process file limit to allow for the specified limit
  # the max number of allowed clients is set to the current file limit
  # minus 32 (as Redis reserves a few file descriptors for internal uses).
  #
  # Once the limit is reached Redis will close all the new connections sending
  # an error 'max number of clients reached'.
  #
  # maxclients 10000
  
  # Don't use more memory than the specified amount of bytes.
  # When the memory limit is reached Redis will try to remove keys
  # accordingly to the eviction policy selected (see maxmemmory-policy).
  #
  # If Redis can't remove keys according to the policy, or if the policy is
  # set to 'noeviction', Redis will start to reply with errors to commands
  # that would use more memory, like SET, LPUSH, and so on, and will continue
  # to reply to read-only commands like GET.
  #
  # This option is usually useful when using Redis as an LRU cache, or to set
  # an hard memory limit for an instance (using the 'noeviction' policy).
  #
  # WARNING: If you have slaves attached to an instance with maxmemory on,
  # the size of the output buffers needed to feed the slaves are subtracted
  # from the used memory count, so that network problems / resyncs will
  # not trigger a loop where keys are evicted, and in turn the output
  # buffer of slaves is full with DELs of keys evicted triggering the deletion
  # of more keys, and so forth until the database is completely emptied.
  #
  # In short... if you have slaves attached it is suggested that you set a lower
  # limit for maxmemory so that there is some free RAM on the system for slave
  # output buffers (but this is not needed if the policy is 'noeviction').
  #
  # maxmemory &lt;bytes&gt;
  
  # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
  # is reached. You can select among five behaviors:
  # 
  # volatile-lru -&gt; remove the key with an expire set using an LRU algorithm
  # allkeys-lru -&gt; remove any key accordingly to the LRU algorithm
  # volatile-random -&gt; remove a random key with an expire set
  # allkeys-random -&gt; remove a random key, any key
  # volatile-ttl -&gt; remove the key with the nearest expire time (minor TTL)
  # noeviction -&gt; don't expire at all, just return an error on write operations
  # 
  # Note: with any of the above 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
  
  # 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
  
  ############################## APPEND ONLY MODE ###############################
  
  # By default Redis asynchronously dumps the dataset on disk. This mode is
  # good enough in many applications, but an issue with the Redis process or
  # a power outage may result into a few minutes of writes lost (depending on
  # the configured save points).
  #
  # The Append Only File is an alternative persistence mode that provides
  # much better durability. For instance using the default data fsync policy
  # (see later in the config file) Redis can lose just one second of writes in a
  # dramatic event like a server power outage, or a single write if something
  # wrong with the Redis process itself happens, but the operating system is
  # still running correctly.
  #
  # AOF and RDB persistence can be enabled at the same time without problems.
  # If the AOF is enabled on startup Redis will load the AOF, that is the file
  # with the better durability guarantees.
  #
  # Please check http://redis.io/topics/persistence for more information.
  
  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 one time every second. Compromise.
  #
  # The default is "everysec", as 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 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.
  #
  # More details please check the following article:
  # http://antirez.com/post/redis-persistence-demystified.html
  #
  # 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". In practical terms, this means that it is
  # possible to lose 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
  
  # Automatic rewrite of the append only file.
  # Redis is able to automatically rewrite the log file implicitly calling
  # BGREWRITEAOF when the AOF log size grows by the specified percentage.
  # 
  # This is how it works: Redis remembers the size of the AOF file after the
  # latest rewrite (if no rewrite has happened since the restart, the size of
  # the AOF at startup is used).
  #
  # This base size is compared to the current size. If the current size is
  # bigger than the specified percentage, the rewrite is triggered. Also
  # you need to specify a minimal size for the AOF file to be rewritten, this
  # is useful to avoid rewriting the AOF file even if the percentage increase
  # is reached but it is still pretty small.
  #
  # Specify a percentage of zero in order to disable the automatic AOF
  # rewrite feature.
  
  auto-aof-rewrite-percentage 100
  auto-aof-rewrite-min-size 64mb
  
  ################################ LUA SCRIPTING  ###############################
  
  # Max execution time of a Lua script in milliseconds.
  #
  # If the maximum execution time is reached Redis will log that a script is
  # still in execution after the maximum allowed time and will start to
  # reply to queries with an error.
  #
  # When a long running script exceed the maximum execution time only the
  # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
  # used to stop a script that did not yet called write commands. The second
  # is the only way to shut down the server in the case a write commands was
  # already issue by the script but the user don't want to wait for the natural
  # termination of the script.
  #
  # Set it to 0 or a negative value for unlimited execution without warnings.
  lua-time-limit 5000
  
  ################################## SLOW LOG ###################################
  
  # The Redis Slow Log is a system to log queries that exceeded a specified
  # execution time. The execution time does not include the I/O operations
  # like talking with the client, sending the reply and so forth,
  # but just the time needed to actually execute the command (this is the only
  # stage of command execution where the thread is blocked and can not serve
  # other requests in the meantime).
  # 
  # You can configure the slow log with two parameters: one tells Redis
  # what is the execution time, in microseconds, to exceed in order for the
  # command to get logged, and the other parameter is the length of the
  # slow log. When a new command is logged the oldest one is removed from the
  # queue of logged commands.
  
  # The following time is expressed in microseconds, so 1000000 is equivalent
  # to one second. Note that a negative number disables the slow log, while
  # a value of zero forces the logging of every command.
  slowlog-log-slower-than 10000
  
  # There is no limit to this length. Just be aware that it will consume memory.
  # You can reclaim memory used by the slow log with SLOWLOG RESET.
  slowlog-max-len 128
  
  ############################### ADVANCED CONFIG ###############################
  
  # Hashes are encoded using a memory efficient data structure when they have a
  # small number of entries, and the biggest entry does not exceed a given
  # threshold. These thresholds can be configured using the following directives.
  hash-max-ziplist-entries 512
  hash-max-ziplist-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
  
  # Similarly to hashes and lists, sorted sets are also specially encoded in
  # order to save a lot of space. This encoding is only used when the length and
  # elements of a sorted set are below the following limits:
  zset-max-ziplist-entries 128
  zset-max-ziplist-value 64
  
  # 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 rehashing, 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
  
  # The client output buffer limits can be used to force disconnection of clients
  # that are not reading data from the server fast enough for some reason (a
  # common reason is that a Pub/Sub client can't consume messages as fast as the
  # publisher can produce them).
  #
  # The limit can be set differently for the three different classes of clients:
  #
  # normal -&gt; normal clients
  # slave  -&gt; slave clients and MONITOR clients
  # pubsub -&gt; clients subcribed to at least one pubsub channel or pattern
  #
  # The syntax of every client-output-buffer-limit directive is the following:
  #
  # client-output-buffer-limit &lt;class&gt; &lt;hard limit&gt; &lt;soft limit&gt; &lt;soft seconds&gt;
  #
  # A client is immediately disconnected once the hard limit is reached, or if
  # the soft limit is reached and remains reached for the specified number of
  # seconds (continuously).
  # So for instance if the hard limit is 32 megabytes and the soft limit is
  # 16 megabytes / 10 seconds, the client will get disconnected immediately
  # if the size of the output buffers reach 32 megabytes, but will also get
  # disconnected if the client reaches 16 megabytes and continuously overcomes
  # the limit for 10 seconds.
  #
  # By default normal clients are not limited because they don't receive data
  # without asking (in a push way), but just after a request, so only
  # asynchronous clients may create a scenario where data is requested faster
  # than it can read.
  #
  # Instead there is a default limit for pubsub and slave clients, since
  # subscribers and slaves receive data in a push fashion.
  #
  # Both the hard or the soft limit can be disabled by setting them to zero.
  client-output-buffer-limit normal 0 0 0
  client-output-buffer-limit slave 256mb 64mb 60
  client-output-buffer-limit pubsub 32mb 8mb 60
  
  # Redis calls an internal function to perform many background tasks, like
  # closing connections of clients in timeot, purging expired keys that are
  # never requested, and so forth.
  #
  # Not all tasks are perforemd with the same frequency, but Redis checks for
  # tasks to perform accordingly to the specified "hz" value.
  #
  # By default "hz" is set to 10. Raising the value will use more CPU when
  # Redis is idle, but at the same time will make Redis more responsive when
  # there are many keys expiring at the same time, and timeouts may be
  # handled with more precision.
  #
  # The range is between 1 and 500, however a value over 100 is usually not
  # a good idea. Most users should use the default of 10 and raise this up to
  # 100 only in environments where very low latency is required.
  hz 10
  
  # When a child rewrites the AOF file, if the following option is enabled
  # the file will be fsync-ed every 32 MB of data generated. This is useful
  # in order to commit the file to the disk more incrementally and avoid
  # big latency spikes.
  aof-rewrite-incremental-fsync 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
  </code></pre>