| 0.7.4 |
| ===== |
| |
| Upgrading |
| --------- |
| - Nothing specific to 0.7.4, but see 0.7.3 Upgrading if upgrading |
| from earlier than 0.7.1. |
| |
| Features |
| -------- |
| - Output to Pig is now supported as well as input |
| |
| |
| |
| 0.7.3 |
| ===== |
| |
| Upgrading |
| --------- |
| - 0.7.1 and 0.7.2 shipped with a bug that caused incorrect row-level |
| bloom filters to be generated when compacting sstables generated |
| with earlier versions. This would manifest in IOExceptions during |
| column name-based queries. 0.7.3 provides "nodetool scrub" to |
| rebuild sstables with correct bloom filters, with no data lost. |
| (If your cluster was never on 0.7.0 or earlier, you don't have to |
| worry about this.) Note that nodetool scrub will snapshot your |
| data files before rebuilding, just in case. |
| |
| |
| 0.7.1 |
| ===== |
| |
| Upgrading |
| --------- |
| - 0.7.1 is completely backwards compatible with 0.7.0. Just restart |
| each node with the new version, one at a time. (The cluster does |
| not all need to be upgraded simultaneously.) |
| |
| Features |
| -------- |
| - added flush_largest_memtables_at and reduce_cache_sizes_at options |
| to cassandra.yaml as an escape valve for memory pressure |
| - added option to specify -Dcassandra.join_ring=false on startup |
| to allow "warm spare" nodes or performing JMX maintenance before |
| joining the ring |
| |
| Performance |
| ----------- |
| - Disk writes and sequential scans avoid polluting page cache |
| (requires JNA to be enabled) |
| - Cassandra performs writes efficiently across datacenters by |
| sending a single copy of the mutation and having the recipient |
| forward that to other replicas in its datacenter. |
| - Improved network buffering |
| - Reduced lock contention on memtable flush |
| - Optimized supercolumn deserialization |
| - Zero-copy reads from mmapped sstable files |
| - Explicitly set higher JVM new generation size |
| - Reduced i/o contention during saving of caches |
| |
| |
| 0.7.0 |
| ===== |
| |
| Features |
| -------- |
| - Secondary indexes (indexes on column values) are now supported |
| - Row size limit increased from 2GB to 2 billion columns. rows |
| are no longer read into memory during compaction. |
| - Keyspace and ColumnFamily definitions may be added and modified live |
| - Streaming data for repair or node movement no longer requires |
| anticompaction step first |
| - NetworkTopologyStrategy (formerly DatacenterShardStrategy) is ready for |
| use, enabling ConsistencyLevel.DCQUORUM and DCQUORUMSYNC. See comments |
| in `cassandra.yaml.` |
| - Optional per-Column time-to-live field allows expiring data without |
| have to issue explicit remove commands |
| - `truncate` thrift method allows clearing an entire ColumnFamily at once |
| - Hadoop OutputFormat and Streaming [non-jvm map/reduce via stdin/out] |
| support |
| - Up to 8x faster reads from row cache |
| - A new ByteOrderedPartitioner supports bytes keys with arbitrary content, |
| and orders keys by their byte value. This should be used in new |
| deployments instead of OrderPreservingPartitioner. |
| - Optional round-robin scheduling between keyspaces for multitenant |
| clusters |
| - Dynamic endpoint snitch mitigates the impact of impaired nodes |
| - New `IntegerType`, faster than LongType and allows integers of |
| both less and more bits than Long's 64 |
| - A revamped authentication system that decouples authorization and |
| allows finer-grained control of resources. |
| |
| Upgrading |
| --------- |
| The Thrift API has changed in incompatible ways; see below, and refer |
| to http://wiki.apache.org/cassandra/ClientOptions for a list of |
| higher-level clients that have been updated to support the 0.7 API. |
| |
| The Cassandra inter-node protocol is incompatible with 0.6.x |
| releases (and with 0.7 beta1), meaning you will have to bring your |
| cluster down prior to upgrading: you cannot mix 0.6 and 0.7 nodes. |
| |
| The hints schema was changed from 0.6 to 0.7. Cassandra automatically |
| snapshots and then truncates the hints column family as part of |
| starting up 0.7 for the first time. |
| |
| Keyspace and ColumnFamily definitions are stored in the system |
| keyspace, rather than the configuration file. |
| |
| The process to upgrade is: |
| 1) run "nodetool drain" on _each_ 0.6 node. When drain finishes (log |
| message "Node is drained" appears), stop the process. |
| 2) Convert your storage-conf.xml to the new cassandra.yaml using |
| "bin/config-converter". |
| 3) Rename any of your keyspace or column family names that do not adhere |
| to the '^\w+' regex convention. |
| 4) Start up your cluster with the 0.7 version. |
| 5) Initialize your Keyspace and ColumnFamily definitions using |
| "bin/schematool <host> <jmxport> import". _You only need to do |
| this to one node_. |
| |
| Thrift API |
| ---------- |
| - The Cassandra server now defaults to framed mode, rather than |
| unframed. Unframed is obsolete and will be removed in the next |
| major release. |
| - The Cassandra Thrift interface file has been updated for Thrift 0.5. |
| If you are compiling your own client code from the interface, you |
| will need to upgrade the Thrift compiler to match. |
| - Row keys are now bytes: keys stored by versions prior to 0.7.0 will be |
| returned as UTF-8 encoded bytes. OrderPreservingPartitioner and |
| CollatingOrderPreservingPartitioner continue to expect that keys contain |
| UTF-8 encoded strings, but RandomPartitioner now works on any key data. |
| - keyspace parameters have been replaced with the per-connection |
| set_keyspace method. |
| - The return type for login() is now AccessLevel. |
| - The get_string_property() method has been removed. |
| - The get_string_list_property() method has been removed. |
| |
| Configuraton |
| ------------ |
| - Configuration file renamed to cassandra.yaml and log4j.properties to |
| log4j-server.properties |
| - PropertyFileSnitch configuration file renamed to |
| cassandra-topology.properties |
| - The ThriftAddress and ThriftPort directives have been renamed to |
| RPCAddress and RPCPort respectively. |
| - EndPointSnitch was renamed to RackInferringSnitch. A new SimpleSnitch |
| has been added. |
| - RackUnawareStrategy and RackAwareStrategy have been renamed to |
| SimpleStrategy and OldNetworkTopologyStrategy, respectively. |
| - RowWarningThresholdInMB replaced with in_memory_compaction_limit_in_mb |
| - GCGraceSeconds is now per-ColumnFamily instead of global |
| - Keyspace and column family names that do not confirm to a '^\w+' regex |
| are considered illegal. |
| - Keyspace and column family definitions will need to be loaded via |
| "bin/schematool <host> <jmxport> import". _You only need to do this to |
| one node_. |
| - In addition to an authenticator, an authority must be configured as |
| well. Users of SimpleAuthenticator should use SimpleAuthority for this |
| value (the default is AllowAllAuthority, which corresponds with |
| AllowAllAuthenticator). |
| - The format of access.properties has changed, see the sample configuration |
| conf/access.properties for documentation on the new format. |
| |
| |
| JMX |
| --- |
| - StreamingService moved from o.a.c.streaming to o.a.c.service |
| - GMFD renamed to GOSSIP_STAGE |
| - {Min,Mean,Max}RowCompactedSize renamed to {Min,Mean,Max}RowSize |
| since it no longer has to wait til compaction to be computed |
| |
| Other |
| ----- |
| - If extending AbstractType, make sure you follow the singleton pattern |
| followed by Cassandra core AbstractType classes: provide a public |
| static final variable called 'instance'. |
| |
| |
| 0.6.6 |
| ===== |
| |
| Upgrading |
| --------- |
| - As part of the cache-saving feature, a third directory |
| (along with data and commitlog) has been added to the config |
| file. You will need to set and create this directory |
| when restarting your node into 0.6.6. |
| |
| |
| 0.6.1 |
| ===== |
| |
| Upgrading |
| --------- |
| - We try to keep minor versions 100% compatible (data format, |
| commitlog format, network format) within the major series, but |
| we introduced a network-level incompatibility in 0.6.1. |
| Thus, if you are upgrading from 0.6.0 to any higher version |
| (0.6.1, 0.6.2, etc.) then you will need to restart your entire |
| cluster with the new version, instead of being able to do a |
| rolling restart. |
| |
| |
| 0.6.0 |
| ===== |
| |
| Features |
| -------- |
| - row caching: configure with the RowsCached attribute in |
| ColumnFamily definition |
| - Hadoop map/reduce support: see contrib/word_count for an example |
| - experimental authentication support, described under |
| Authenticator in storage.conf |
| |
| Configuraton |
| ------------ |
| - MemtableSizeInMB has been replaced by MemtableThroughputInMB which |
| triggers a memtable flush when the specified amount of data has |
| been written, including overwrites. |
| - MemtableObjectCountInMillions has been replaced by the |
| MemtableOperationsInMillions directive which causes a memtable flush |
| to occur after the specified number of operations. |
| - Like MemtableSizeInMB, BinaryMemtableSizeInMB has been replaced by |
| BinaryMemtableThroughputInMB. |
| - Replication factor is now per-keyspace, rather than global. |
| - KeysCachedFraction is deprecated in favor of KeysCached |
| - RowWarningThresholdInMB added, to warn before very large rows |
| get big enough to threaten node stability |
| |
| Thrift API |
| ---------- |
| - removed deprecated get_key_range method |
| - added batch_mutate meethod |
| - deprecated multiget and batch_insert methods in favor of |
| multiget_slice and batch_mutate, respectively |
| - added ConsistencyLevel.ANY, for when you want write |
| availability even when it may not be readable immediately. |
| Unlike CL.ZERO, though, it will throw an exception if |
| it cannot be written *somewhere*. |
| |
| JMX metrics |
| ----------- |
| - read and write statistics are reported as lifetime totals, |
| instead of averages over the last minute. average-since-last |
| requested are also available for convenience. |
| - cache hit rate statistics are now available from JMX under |
| org.apache.cassandra.db.Caches |
| - compaction JMX metrics are moved to |
| org.apache.cassandra.db.CompactionManager. PendingTasks is now |
| a much better estimate of compactions remaining, and the |
| progress of the current compaction has been added. |
| - commitlog JMX metrics are moved to org.apache.cassandra.db.Commitlog |
| - progress of data streaming during bootstrap, loadbalance, or other |
| data migration, is available under |
| org.apache.cassandra.streaming.StreamingService. |
| See http://wiki.apache.org/cassandra/Streaming for details. |
| |
| Installation/Upgrade |
| -------------------- |
| - 0.6 network traffic is not compatible with earlier versions. You |
| will need to shut down all your nodes at once, upgrade, then restart. |
| |
| |
| |
| 0.5.0 |
| ===== |
| |
| 0. The commitlog format has changed (but sstable format has not). |
| When upgrading from 0.4, empty the commitlog either by running |
| bin/nodeprobe flush on each machine and waiting for the flush to finish, |
| or simply remove the commitlog directory if you only have test data. |
| (If more writes come in after the flush command, starting 0.5 will error |
| out; if that happens, just go back to 0.4 and flush again.) |
| The format changed twice: from 0.4 to beta1, and from beta2 to RC1. |
| |
| .5 The gossip protocol has changed, meaning 0.5 nodes cannot coexist |
| in a cluster of 0.4 nodes or vice versa; you must upgrade your |
| whole cluster at the same time. |
| |
| 1. Bootstrap, move, load balancing, and active repair have been added. |
| See http://wiki.apache.org/cassandra/Operations. When upgrading |
| from 0.4, leave autobootstrap set to false for the first restart |
| of your old nodes. |
| |
| 2. Performance improvements across the board, especially on the write |
| path (over 100% improvement in stress.py throughput). |
| |
| 3. Configuration: |
| - Added "comment" field to ColumnFamily definition. |
| - Added MemtableFlushAfterMinutes, a global replacement for the |
| old per-CF FlushPeriodInMinutes setting |
| - Key cache settings |
| |
| 4. Thrift: |
| - Added get_range_slice, deprecating get_key_range |
| |
| |
| |
| 0.4.2 |
| ===== |
| |
| 1. Improve default garbage collector options significantly -- |
| throughput will be 30% higher or more. |
| |
| |
| |
| 0.4.1 |
| ===== |
| |
| 1. SnapshotBeforeCompaction configuration option allows snapshotting |
| before each compaction, which allows rolling back to any version |
| of the data. |
| |
| |
| |
| 0.4.0 |
| ===== |
| |
| 1. On-disk data format has changed to allow billions of keys/rows per |
| node instead of only millions. The new format is incompatible with 0.3; |
| see 0.3 notes below for how to import data from a 0.3 install. |
| |
| 2. Cassandra now supports multiple keyspaces. Typically you will have |
| one keyspace per application, allowing applications to be able to |
| create and modify ColumnFamilies at will without worrying about |
| collisions with others in the same cluster. |
| |
| 3. Many Thrift API changes and documentation. See |
| http://wiki.apache.org/cassandra/API |
| |
| 4. Removed the web interface in favor of JMX and bin/nodeprobe, which |
| has significantly enhanced functionality. |
| |
| 5. Renamed configuration "<Table>" to "<Keyspace>". |
| |
| 6. Added commitlog fsync; see "<CommitLogSync>" in configuration. |
| |
| |
| |
| 0.3.0 |
| ===== |
| |
| 1. With enough and large enough keys in a ColumnFamily, Cassandra will |
| run out of memory trying to perform compactions (data file merges). |
| The size of what is stored in memory is (S + 16) * (N + M) where S |
| is the size of the key (usually 2 bytes per character), N is the |
| number of keys and M, is the map overhead (which can be guestimated |
| at around 32 bytes per key). |
| So, if you have 10-character keys and 1GB of headroom in your heap |
| space for compaction, you can expect to store about 17M keys |
| before running into problems. |
| See https://issues.apache.org/jira/browse/CASSANDRA-208 |
| |
| 2. Because fixing #1 requires a data file format change, 0.4 will not |
| be binary-compatible with 0.3 data files. A client-side upgrade |
| can be done relatively easily with the following algorithm: |
| for key in old_client.get_key_range(everything): |
| columns = old_client.get_slice or get_slice_super(key, all columns) |
| new_client.batch_insert or batch_insert_super(key, columns) |
| The inner loop can be trivially parallelized for speed. |
| |
| 3. Commitlog does not fsync before reporting a write successful. |
| Using blocking writes mitigates this to some degree, since all |
| nodes that were part of the write quorum would have to fail |
| before sync for data to be lost. |
| See https://issues.apache.org/jira/browse/CASSANDRA-182 |
| |
| Additionally, row size (that is, all the data associated with a single |
| key in a given ColumnFamily) is limited by available memory, because |
| compaction deserializes each row before merging. |
| |
| See https://issues.apache.org/jira/browse/CASSANDRA-16 |
| |