storage-conf.xml

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 ~ under the License.
-->
<Storage>
  <!--======================================================================-->
  <!-- Basic Configuration                                                  -->
  <!--======================================================================-->

  <!-- 
   ~ The name of this cluster.  This is mainly used to prevent machines in
   ~ one logical cluster from joining another.
  -->
  <ClusterName>Twissandra Cluster</ClusterName>

  <!--
   ~ Turn on to make new [non-seed] nodes automatically migrate the right data 
   ~ to themselves.  (If no InitialToken is specified, they will pick one 
   ~ such that they will get half the range of the most-loaded node.)
   ~ If a node starts up without bootstrapping, it will mark itself bootstrapped
   ~ so that you can't subsequently accidently bootstrap a node with
   ~ data on it.  (You can reset this by wiping your data and commitlog
   ~ directories.)
   ~
   ~ Off by default so that new clusters and upgraders from 0.4 don't
   ~ bootstrap immediately.  You should turn this on when you start adding
   ~ new nodes to a cluster that already has data on it.  (If you are upgrading
   ~ from 0.4, start your cluster with it off once before changing it to true.
   ~ Otherwise, no data will be lost but you will incur a lot of unnecessary
   ~ I/O before your cluster starts up.)
  -->
  <AutoBootstrap>false</AutoBootstrap>

  <!--
   ~ Keyspaces and ColumnFamilies:
   ~ A ColumnFamily is the Cassandra concept closest to a relational
   ~ table.  Keyspaces are separate groups of ColumnFamilies.  Except in
   ~ very unusual circumstances you will have one Keyspace per application.

   ~ There is an implicit keyspace named 'system' for Cassandra internals.
  -->
  <Keyspaces>
    <Keyspace Name="Twissandra">
      <!--
       ~ ColumnFamily definitions have one required attribute (Name)
       ~ and several optional ones.
       ~
       ~ The CompareWith attribute tells Cassandra how to sort the columns
       ~ for slicing operations.  The default is BytesType, which is a
       ~ straightforward lexical comparison of the bytes in each column.
       ~ Other options are AsciiType, UTF8Type, LexicalUUIDType, TimeUUIDType,
       ~ and LongType.  You can also specify the fully-qualified class
       ~ name to a class of your choice extending
       ~ org.apache.cassandra.db.marshal.AbstractType.
       ~ 
       ~ SuperColumns have a similar CompareSubcolumnsWith attribute.
       ~ 
       ~ BytesType: Simple sort by byte value.  No validation is performed.
       ~ AsciiType: Like BytesType, but validates that the input can be 
       ~            parsed as US-ASCII.
       ~ UTF8Type: A string encoded as UTF8
       ~ LongType: A 64bit long
       ~ LexicalUUIDType: A 128bit UUID, compared lexically (by byte value)
       ~ TimeUUIDType: a 128bit version 1 UUID, compared by timestamp
       ~
       ~ (To get the closest approximation to 0.3-style supercolumns, you
       ~ would use CompareWith=UTF8Type CompareSubcolumnsWith=LongType.)
       ~
       ~ An optional `Comment` attribute may be used to attach additional
       ~ human-readable information about the column family to its definition.
       ~ 
       ~ The optional KeysCached attribute specifies
       ~ the number of keys per sstable whose locations we keep in
       ~ memory in "mostly LRU" order.  (JUST the key locations, NOT any
       ~ column values.) Specify a fraction (value less than 1), a percentage
       ~ (ending in a % sign) or an absolute number of keys to cache.
       ~ KeysCached defaults to 200000 keys.
       ~
       ~ The optional RowsCached attribute specifies the number of rows
       ~ whose entire contents we cache in memory. Do not use this on
       ~ ColumnFamilies with large rows, or ColumnFamilies with high write:read
       ~ ratios. Specify a fraction (value less than 1), a percentage (ending in
       ~ a % sign) or an absolute number of rows to cache. 
       ~ RowsCached defaults to 0, i.e., row cache is off by default.
       ~
       ~ Remember, when using caches as a percentage, they WILL grow with
       ~ your data set!
      -->
      <ColumnFamily CompareWith="UTF8Type" Name="User"/>
      <ColumnFamily CompareWith="BytesType" Name="Username"/>
      <ColumnFamily CompareWith="BytesType" Name="Friends"/>
      <ColumnFamily CompareWith="BytesType" Name="Followers"/>
      <ColumnFamily CompareWith="UTF8Type" Name="Tweet"/>
      <ColumnFamily CompareWith="LongType" Name="Timeline"/>
      <ColumnFamily CompareWith="LongType" Name="Userline"/>

      <!--
       ~ Strategy: Setting this to the class that implements
       ~ IReplicaPlacementStrategy will change the way the node picker works.
       ~ Out of the box, Cassandra provides
       ~ org.apache.cassandra.locator.RackUnawareStrategy and
       ~ org.apache.cassandra.locator.RackAwareStrategy (place one replica in
       ~ a different datacenter, and the others on different racks in the same
       ~ one.)
      -->
      <ReplicaPlacementStrategy>org.apache.cassandra.locator.RackUnawareStrategy</ReplicaPlacementStrategy>

      <!-- Number of replicas of the data -->
      <ReplicationFactor>1</ReplicationFactor>

      <!--
       ~ EndPointSnitch: Setting this to the class that implements
       ~ AbstractEndpointSnitch, which lets Cassandra know enough
       ~ about your network topology to route requests efficiently.
       ~ Out of the box, Cassandra provides org.apache.cassandra.locator.EndPointSnitch,
       ~ and PropertyFileEndPointSnitch is available in contrib/.
      -->
      <EndPointSnitch>org.apache.cassandra.locator.EndPointSnitch</EndPointSnitch>
        
    </Keyspace>
  </Keyspaces>

  <!--
   ~ Authenticator: any IAuthenticator may be used, including your own as long
   ~ as it is on the classpath.  Out of the box, Cassandra provides
   ~ org.apache.cassandra.auth.AllowAllAuthenticator and,
   ~ org.apache.cassandra.auth.SimpleAuthenticator 
   ~ (SimpleAuthenticator uses access.properties and passwd.properties by
   ~ default).
   ~
   ~ If you don't specify an authenticator, AllowAllAuthenticator is used.
  -->
  <Authenticator>org.apache.cassandra.auth.AllowAllAuthenticator</Authenticator>

  <!--
   ~ Partitioner: any IPartitioner may be used, including your own as long
   ~ as it is on the classpath.  Out of the box, Cassandra provides
   ~ org.apache.cassandra.dht.RandomPartitioner,
   ~ org.apache.cassandra.dht.OrderPreservingPartitioner, and
   ~ org.apache.cassandra.dht.CollatingOrderPreservingPartitioner.
   ~ (CollatingOPP colates according to EN,US rules, not naive byte
   ~ ordering.  Use this as an example if you need locale-aware collation.)
   ~ Range queries require using an order-preserving partitioner.
   ~
   ~ Achtung!  Changing this parameter requires wiping your data
   ~ directories, since the partitioner can modify the sstable on-disk
   ~ format.
  -->
  <Partitioner>org.apache.cassandra.dht.RandomPartitioner</Partitioner>

  <!--
   ~ If you are using an order-preserving partitioner and you know your key
   ~ distribution, you can specify the token for this node to use. (Keys
   ~ are sent to the node with the "closest" token, so distributing your
   ~ tokens equally along the key distribution space will spread keys
   ~ evenly across your cluster.)  This setting is only checked the first
   ~ time a node is started. 

   ~ This can also be useful with RandomPartitioner to force equal spacing
   ~ of tokens around the hash space, especially for clusters with a small
   ~ number of nodes.
  -->
  <InitialToken></InitialToken>

  <!--
   ~ Directories: Specify where Cassandra should store different data on
   ~ disk.  Keep the data disks and the CommitLog disks separate for best
   ~ performance
  -->
  <CommitLogDirectory>/var/lib/cassandra/commitlog</CommitLogDirectory>
  <DataFileDirectories>
      <DataFileDirectory>/var/lib/cassandra/data</DataFileDirectory>
  </DataFileDirectories>


  <!--
   ~ Addresses of hosts that are deemed contact points. Cassandra nodes
   ~ use this list of hosts to find each other and learn the topology of
   ~ the ring. You must change this if you are running multiple nodes!
  -->
  <Seeds>
      <Seed>127.0.0.1</Seed>
  </Seeds>


  <!-- Miscellaneous -->

  <!-- Time to wait for a reply from other nodes before failing the command -->
  <RpcTimeoutInMillis>10000</RpcTimeoutInMillis>
  <!-- Size to allow commitlog to grow to before creating a new segment -->
  <CommitLogRotationThresholdInMB>128</CommitLogRotationThresholdInMB>


  <!-- Local hosts and ports -->

  <!-- 
   ~ Address to bind to and tell other nodes to connect to.  You _must_
   ~ change this if you want multiple nodes to be able to communicate!  
   ~
   ~ Leaving it blank leaves it up to InetAddress.getLocalHost(). This
   ~ will always do the Right Thing *if* the node is properly configured
   ~ (hostname, name resolution, etc), and the Right Thing is to use the
   ~ address associated with the hostname (it might not be).
  -->
  <ListenAddress>localhost</ListenAddress>
  <!-- internal communications port -->
  <StoragePort>7000</StoragePort>

  <!--
   ~ The address to bind the Thrift RPC service to. Unlike ListenAddress
   ~ above, you *can* specify 0.0.0.0 here if you want Thrift to listen on
   ~ all interfaces.
   ~
   ~ Leaving this blank has the same effect it does for ListenAddress,
   ~ (i.e. it will be based on the configured hostname of the node).
  -->
  <ThriftAddress>localhost</ThriftAddress>
  <!-- Thrift RPC port (the port clients connect to). -->
  <ThriftPort>9160</ThriftPort>
  <!-- 
   ~ Whether or not to use a framed transport for Thrift. If this option
   ~ is set to true then you must also use a framed transport on the 
   ~ client-side, (framed and non-framed transports are not compatible).
  -->
  <ThriftFramedTransport>true</ThriftFramedTransport>


  <!--======================================================================-->
  <!-- Memory, Disk, and Performance                                        -->
  <!--======================================================================-->

  <!--
   ~ Access mode.  mmapped i/o is substantially faster, but only practical on
   ~ a 64bit machine (which notably does not include EC2 "small" instances)
   ~ or relatively small datasets.  "auto", the safe choice, will enable
   ~ mmapping on a 64bit JVM.  Other values are "mmap", "mmap_index_only"
   ~ (which may allow you to get part of the benefits of mmap on a 32bit
   ~ machine by mmapping only index files) and "standard".
   ~ (The buffer size settings that follow only apply to standard,
   ~ non-mmapped i/o.)
   -->
  <DiskAccessMode>auto</DiskAccessMode>

  <!--
   ~ Size of compacted row above which to log a warning.  (If compacted
   ~ rows do not fit in memory, Cassandra will crash.  This is explained
   ~ in http://wiki.apache.org/cassandra/CassandraLimitations and is
   ~ scheduled to be fixed in 0.7.)
  -->
  <RowWarningThresholdInMB>512</RowWarningThresholdInMB>

  <!--
   ~ Buffer size to use when performing contiguous column slices. Increase
   ~ this to the size of the column slices you typically perform. 
   ~ (Name-based queries are performed with a buffer size of 
   ~ ColumnIndexSizeInKB.)
  -->
  <SlicedBufferSizeInKB>64</SlicedBufferSizeInKB>

  <!--
   ~ Buffer size to use when flushing memtables to disk. (Only one 
   ~ memtable is ever flushed at a time.) Increase (decrease) the index
   ~ buffer size relative to the data buffer if you have few (many) 
   ~ columns per key.  Bigger is only better _if_ your memtables get large
   ~ enough to use the space. (Check in your data directory after your
   ~ app has been running long enough.) -->
  <FlushDataBufferSizeInMB>32</FlushDataBufferSizeInMB>
  <FlushIndexBufferSizeInMB>8</FlushIndexBufferSizeInMB>

  <!--
   ~ Add column indexes to a row after its contents reach this size.
   ~ Increase if your column values are large, or if you have a very large
   ~ number of columns.  The competing causes are, Cassandra has to
   ~ deserialize this much of the row to read a single column, so you want
   ~ it to be small - at least if you do many partial-row reads - but all
   ~ the index data is read for each access, so you don't want to generate
   ~ that wastefully either.
  -->
  <ColumnIndexSizeInKB>64</ColumnIndexSizeInKB>

  <!--
   ~ Flush memtable after this much data has been inserted, including
   ~ overwritten data.  There is one memtable per column family, and 
   ~ this threshold is based solely on the amount of data stored, not
   ~ actual heap memory usage (there is some overhead in indexing the
   ~ columns).
  -->
  <MemtableThroughputInMB>64</MemtableThroughputInMB>
  <!--
   ~ Throughput setting for Binary Memtables.  Typically these are
   ~ used for bulk load so you want them to be larger.
  -->
  <BinaryMemtableThroughputInMB>256</BinaryMemtableThroughputInMB>
  <!--
   ~ The maximum number of columns in millions to store in memory per
   ~ ColumnFamily before flushing to disk.  This is also a per-memtable
   ~ setting.  Use with MemtableThroughputInMB to tune memory usage.
  -->
  <MemtableOperationsInMillions>0.3</MemtableOperationsInMillions>
  <!--
   ~ The maximum time to leave a dirty memtable unflushed.
   ~ (While any affected columnfamilies have unflushed data from a
   ~ commit log segment, that segment cannot be deleted.)
   ~ This needs to be large enough that it won't cause a flush storm
   ~ of all your memtables flushing at once because none has hit
   ~ the size or count thresholds yet.  For production, a larger
   ~ value such as 1440 is recommended.
  -->
  <MemtableFlushAfterMinutes>60</MemtableFlushAfterMinutes>

  <!--
   ~ Unlike most systems, in Cassandra writes are faster than reads, so
   ~ you can afford more of those in parallel.  A good rule of thumb is 2
   ~ concurrent reads per processor core.  Increase ConcurrentWrites to
   ~ the number of clients writing at once if you enable CommitLogSync +
   ~ CommitLogSyncDelay. -->
  <ConcurrentReads>8</ConcurrentReads>
  <ConcurrentWrites>32</ConcurrentWrites>

  <!--
   ~ CommitLogSync may be either "periodic" or "batch."  When in batch
   ~ mode, Cassandra won't ack writes until the commit log has been
   ~ fsynced to disk.  It will wait up to CommitLogSyncBatchWindowInMS
   ~ milliseconds for other writes, before performing the sync.

   ~ This is less necessary in Cassandra than in traditional databases
   ~ since replication reduces the odds of losing data from a failure
   ~ after writing the log entry but before it actually reaches the disk.
   ~ So the other option is "periodic," where writes may be acked immediately
   ~ and the CommitLog is simply synced every CommitLogSyncPeriodInMS
   ~ milliseconds.
  -->
  <CommitLogSync>periodic</CommitLogSync>
  <!--
   ~ Interval at which to perform syncs of the CommitLog in periodic mode.
   ~ Usually the default of 10000ms is fine; increase it if your i/o
   ~ load is such that syncs are taking excessively long times.
  -->
  <CommitLogSyncPeriodInMS>10000</CommitLogSyncPeriodInMS>
  <!--
   ~ Delay (in milliseconds) during which additional commit log entries
   ~ may be written before fsync in batch mode.  This will increase
   ~ latency slightly, but can vastly improve throughput where there are
   ~ many writers.  Set to zero to disable (each entry will be synced
   ~ individually).  Reasonable values range from a minimal 0.1 to 10 or
   ~ even more if throughput matters more than latency.
  -->
  <!-- <CommitLogSyncBatchWindowInMS>1</CommitLogSyncBatchWindowInMS> --> 

  <!--
   ~ Time to wait before garbage-collection deletion markers.  Set this to
   ~ a large enough value that you are confident that the deletion marker
   ~ will be propagated to all replicas by the time this many seconds has
   ~ elapsed, even in the face of hardware failures.  The default value is
   ~ ten days.
  -->
  <GCGraceSeconds>864000</GCGraceSeconds>
</Storage>