| .. Licensed to the Apache Software Foundation (ASF) under one |
| .. or more contributor license agreements. See the NOTICE file |
| .. distributed with this work for additional information |
| .. regarding copyright ownership. The ASF licenses this file |
| .. to you under the Apache License, Version 2.0 (the |
| .. "License"); you may not use this file except in compliance |
| .. with the License. You may obtain a copy of the License at |
| .. |
| .. http://www.apache.org/licenses/LICENSE-2.0 |
| .. |
| .. Unless required by applicable law or agreed to in writing, software |
| .. distributed under the License is distributed on an "AS IS" BASIS, |
| .. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| .. See the License for the specific language governing permissions and |
| .. limitations under the License. |
| |
| sstablemetadata |
| --------------- |
| |
| Print information about an sstable from the related Statistics.db and Summary.db files to standard output. |
| |
| ref: https://issues.apache.org/jira/browse/CASSANDRA-7159 and https://issues.apache.org/jira/browse/CASSANDRA-10838 |
| |
| Cassandra must be stopped before this tool is executed, or unexpected results will occur. Note: the script does not verify that Cassandra is stopped. |
| |
| Usage |
| ^^^^^ |
| |
| sstablemetadata <options> <sstable filename(s)> |
| |
| ========================= ================================================================================ |
| --gc_grace_seconds <arg> The gc_grace_seconds to use when calculating droppable tombstones |
| ========================= ================================================================================ |
| |
| Print all the metadata |
| ^^^^^^^^^^^^^^^^^^^^^^ |
| |
| Run sstablemetadata against the *Data.db file(s) related to a table. If necessary, find the *Data.db file(s) using sstableutil. |
| |
| Example:: |
| |
| sstableutil keyspace1 standard1 | grep Data |
| /var/lib/cassandra/data/keyspace1/standard1-f6845640a6cb11e8b6836d2c86545d91/mc-1-big-Data.db |
| |
| sstablemetadata /var/lib/cassandra/data/keyspace1/standard1-f6845640a6cb11e8b6836d2c86545d91/mc-1-big-Data.db |
| |
| SSTable: /var/lib/cassandra/data/keyspace1/standard1-f6845640a6cb11e8b6836d2c86545d91/mc-1-big |
| Partitioner: org.apache.cassandra.dht.Murmur3Partitioner |
| Bloom Filter FP chance: 0.010000 |
| Minimum timestamp: 1535025576141000 |
| Maximum timestamp: 1535025604309000 |
| SSTable min local deletion time: 2147483647 |
| SSTable max local deletion time: 2147483647 |
| Compressor: org.apache.cassandra.io.compress.LZ4Compressor |
| TTL min: 86400 |
| TTL max: 86400 |
| First token: -9223004712949498654 (key=39373333373831303130) |
| Last token: 9222554117157811897 (key=4f3438394e39374d3730) |
| Estimated droppable tombstones: 0.9188263888888889 |
| SSTable Level: 0 |
| Repaired at: 0 |
| Replay positions covered: {CommitLogPosition(segmentId=1535025390651, position=226400)=CommitLogPosition(segmentId=1535025390651, position=6849139)} |
| totalColumnsSet: 100000 |
| totalRows: 20000 |
| Estimated tombstone drop times: |
| 1535039100: 80390 |
| 1535039160: 5645 |
| 1535039220: 13965 |
| Count Row Size Cell Count |
| 1 0 0 |
| 2 0 0 |
| 3 0 0 |
| 4 0 0 |
| 5 0 20000 |
| 6 0 0 |
| 7 0 0 |
| 8 0 0 |
| 10 0 0 |
| 12 0 0 |
| 14 0 0 |
| 17 0 0 |
| 20 0 0 |
| 24 0 0 |
| 29 0 0 |
| 35 0 0 |
| 42 0 0 |
| 50 0 0 |
| 60 0 0 |
| 72 0 0 |
| 86 0 0 |
| 103 0 0 |
| 124 0 0 |
| 149 0 0 |
| 179 0 0 |
| 215 0 0 |
| 258 20000 0 |
| 310 0 0 |
| 372 0 0 |
| 446 0 0 |
| 535 0 0 |
| 642 0 0 |
| 770 0 0 |
| 924 0 0 |
| 1109 0 0 |
| 1331 0 0 |
| 1597 0 0 |
| 1916 0 0 |
| 2299 0 0 |
| 2759 0 0 |
| 3311 0 0 |
| 3973 0 0 |
| 4768 0 0 |
| 5722 0 0 |
| 6866 0 0 |
| 8239 0 0 |
| 9887 0 0 |
| 11864 0 0 |
| 14237 0 0 |
| 17084 0 0 |
| 20501 0 0 |
| 24601 0 0 |
| 29521 0 0 |
| 35425 0 0 |
| 42510 0 0 |
| 51012 0 0 |
| 61214 0 0 |
| 73457 0 0 |
| 88148 0 0 |
| 105778 0 0 |
| 126934 0 0 |
| 152321 0 0 |
| 182785 0 0 |
| 219342 0 0 |
| 263210 0 0 |
| 315852 0 0 |
| 379022 0 0 |
| 454826 0 0 |
| 545791 0 0 |
| 654949 0 0 |
| 785939 0 0 |
| 943127 0 0 |
| 1131752 0 0 |
| 1358102 0 0 |
| 1629722 0 0 |
| 1955666 0 0 |
| 2346799 0 0 |
| 2816159 0 0 |
| 3379391 0 0 |
| 4055269 0 0 |
| 4866323 0 0 |
| 5839588 0 0 |
| 7007506 0 0 |
| 8409007 0 0 |
| 10090808 0 0 |
| 12108970 0 0 |
| 14530764 0 0 |
| 17436917 0 0 |
| 20924300 0 0 |
| 25109160 0 0 |
| 30130992 0 0 |
| 36157190 0 0 |
| 43388628 0 0 |
| 52066354 0 0 |
| 62479625 0 0 |
| 74975550 0 0 |
| 89970660 0 0 |
| 107964792 0 0 |
| 129557750 0 0 |
| 155469300 0 0 |
| 186563160 0 0 |
| 223875792 0 0 |
| 268650950 0 0 |
| 322381140 0 0 |
| 386857368 0 0 |
| 464228842 0 0 |
| 557074610 0 0 |
| 668489532 0 0 |
| 802187438 0 0 |
| 962624926 0 0 |
| 1155149911 0 0 |
| 1386179893 0 0 |
| 1663415872 0 0 |
| 1996099046 0 0 |
| 2395318855 0 0 |
| 2874382626 0 |
| 3449259151 0 |
| 4139110981 0 |
| 4966933177 0 |
| 5960319812 0 |
| 7152383774 0 |
| 8582860529 0 |
| 10299432635 0 |
| 12359319162 0 |
| 14831182994 0 |
| 17797419593 0 |
| 21356903512 0 |
| 25628284214 0 |
| 30753941057 0 |
| 36904729268 0 |
| 44285675122 0 |
| 53142810146 0 |
| 63771372175 0 |
| 76525646610 0 |
| 91830775932 0 |
| 110196931118 0 |
| 132236317342 0 |
| 158683580810 0 |
| 190420296972 0 |
| 228504356366 0 |
| 274205227639 0 |
| 329046273167 0 |
| 394855527800 0 |
| 473826633360 0 |
| 568591960032 0 |
| 682310352038 0 |
| 818772422446 0 |
| 982526906935 0 |
| 1179032288322 0 |
| 1414838745986 0 |
| Estimated cardinality: 20196 |
| EncodingStats minTTL: 0 |
| EncodingStats minLocalDeletionTime: 1442880000 |
| EncodingStats minTimestamp: 1535025565275000 |
| KeyType: org.apache.cassandra.db.marshal.BytesType |
| ClusteringTypes: [org.apache.cassandra.db.marshal.UTF8Type] |
| StaticColumns: {C3:org.apache.cassandra.db.marshal.BytesType, C4:org.apache.cassandra.db.marshal.BytesType, C0:org.apache.cassandra.db.marshal.BytesType, C1:org.apache.cassandra.db.marshal.BytesType, C2:org.apache.cassandra.db.marshal.BytesType} |
| RegularColumns: {} |
| |
| Specify gc grace seconds |
| ^^^^^^^^^^^^^^^^^^^^^^^^ |
| |
| To see the ratio of droppable tombstones given a configured gc grace seconds, use the gc_grace_seconds option. Because the sstablemetadata tool doesn't access the schema directly, this is a way to more accurately estimate droppable tombstones -- for example, if you pass in gc_grace_seconds matching what is configured in the schema. The gc_grace_seconds value provided is subtracted from the curent machine time (in seconds). |
| |
| ref: https://issues.apache.org/jira/browse/CASSANDRA-12208 |
| |
| Example:: |
| |
| sstablemetadata /var/lib/cassandra/data/keyspace1/standard1-41b52700b4ed11e896476d2c86545d91/mc-12-big-Data.db | grep "Estimated tombstone drop times" -A4 |
| Estimated tombstone drop times: |
| 1536599100: 1 |
| 1536599640: 1 |
| 1536599700: 2 |
| |
| echo $(date +%s) |
| 1536602005 |
| |
| # if gc_grace_seconds was configured at 100, all of the tombstones would be currently droppable |
| sstablemetadata --gc_grace_seconds 100 /var/lib/cassandra/data/keyspace1/standard1-41b52700b4ed11e896476d2c86545d91/mc-12-big-Data.db | grep "Estimated droppable tombstones" |
| Estimated droppable tombstones: 4.0E-5 |
| |
| # if gc_grace_seconds was configured at 4700, some of the tombstones would be currently droppable |
| sstablemetadata --gc_grace_seconds 4700 /var/lib/cassandra/data/keyspace1/standard1-41b52700b4ed11e896476d2c86545d91/mc-12-big-Data.db | grep "Estimated droppable tombstones" |
| Estimated droppable tombstones: 9.61111111111111E-6 |
| |
| # if gc_grace_seconds was configured at 100, none of the tombstones would be currently droppable |
| sstablemetadata --gc_grace_seconds 5000 /var/lib/cassandra/data/keyspace1/standard1-41b52700b4ed11e896476d2c86545d91/mc-12-big-Data.db | grep "Estimated droppable tombstones" |
| Estimated droppable tombstones: 0.0 |
| |
| Explanation of each value printed above |
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| |
| =================================== ================================================================================ |
| Value Explanation |
| =================================== ================================================================================ |
| SSTable prefix of the sstable filenames related to this sstable |
| Partitioner partitioner type used to distribute data across nodes; defined in cassandra.yaml |
| Bloom Filter FP precision of Bloom filter used in reads; defined in the table definition |
| Minimum timestamp minimum timestamp of any entry in this sstable, in epoch microseconds |
| Maximum timestamp maximum timestamp of any entry in this sstable, in epoch microseconds |
| SSTable min local deletion time minimum timestamp of deletion date, based on TTL, in epoch seconds |
| SSTable max local deletion time maximum timestamp of deletion date, based on TTL, in epoch seconds |
| Compressor blank (-) by default; if not blank, indicates type of compression enabled on the table |
| TTL min time-to-live in seconds; default 0 unless defined in the table definition |
| TTL max time-to-live in seconds; default 0 unless defined in the table definition |
| First token lowest token and related key found in the sstable summary |
| Last token highest token and related key found in the sstable summary |
| Estimated droppable tombstones ratio of tombstones to columns, using configured gc grace seconds if relevant |
| SSTable level compaction level of this sstable, if leveled compaction (LCS) is used |
| Repaired at the timestamp this sstable was marked as repaired via sstablerepairedset, in epoch milliseconds |
| Replay positions covered the interval of time and commitlog positions related to this sstable |
| totalColumnsSet number of cells in the table |
| totalRows number of rows in the table |
| Estimated tombstone drop times approximate number of rows that will expire, ordered by epoch seconds |
| Count Row Size Cell Count two histograms in two columns; one represents distribution of Row Size |
| and the other represents distribution of Cell Count |
| Estimated cardinality an estimate of unique values, used for compaction |
| EncodingStats* minTTL in epoch milliseconds |
| EncodingStats* minLocalDeletionTime in epoch seconds |
| EncodingStats* minTimestamp in epoch microseconds |
| KeyType the type of partition key, useful in reading and writing data |
| from/to storage; defined in the table definition |
| ClusteringTypes the type of clustering key, useful in reading and writing data |
| from/to storage; defined in the table definition |
| StaticColumns a list of the shared columns in the table |
| RegularColumns a list of non-static, non-key columns in the table |
| =================================== ================================================================================ |
| * For the encoding stats values, the delta of this and the current epoch time is used when encoding and storing data in the most optimal way. |
| |
| |
| |
