cassandra-sstable-tools
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Published
20 hours ago •
instaclustr
instaclustr
Tools for working with sstables
Instaclustr SSTable tools
https://www.instaclustr.com/update-released-instaclustr-sstable-analysis-tools-apache-cassandra/ https://www.instaclustr.com/instaclustr-open-sources-cassandra-sstable-analysis-tools/
Compile
$ git clone [email protected]:instaclustr/cassandra-sstable-tools.git
$ cd cassandra-sstable-tools
# Select the correct branch for major version (default is cassandra-4.0)
$ git checkout cassandra-4.0
$ mvn clean install
Install
Copy ic-sstable-tools.jar to Cassandra JAR folder, eg. /usr/share/cassandra/lib
Copy the bin/ic-sstable-tools script into your $PATH
We also offer RPM and DEB packages. In case you install them, you do not need to execute steps above, obviously.
Documentation
$ ./bin/ic-sstable-tools
Missing required sub-command.
Usage: <main class> [-hV] [COMMAND]
-h, --help Show this help message and exit.
-V, --version Print version information and exit.
Commands:
cfstats Detailed statistics about cells in a column family
pstats Partition size statistics for a column family
purge Statistics about reclaimable data for a column family
sstables Print out metadata for sstables the belong to a column family
summary Summary information about all column families including how much of the data is repaired
If you want invoke help command for each subcommand, do it like:
$ ./bin/ic-sstable-tools help cfstats
summary
Provides summary information about all column families. Useful for finding the largest column families and how much data has been repaired by incremental repairs.
Usage
ic-sstable-tools summary
Output
| Column | Description |
|---|---|
| Keyspace | Keyspace the column family belongs to |
| Column Family | Name of column family |
| SSTables | Number of sstables on this node for the column family |
| Disk Size | Compressed size on disk for this node |
| Data Size | Uncompressed size of the data for this node |
| Last Repaired | Maximum repair timestamp on sstables |
| Repair % | Percentage of data marked as repaired |
sstables
Print out sstable metadata for a column family. Useful in helping to tune compaction settings.
Usage
ic-sstable-tools sstables <keyspace> <column-family>
Output
| Column | Description |
|---|---|
| SSTable | Data.db filename of sstable |
| Disk Size | Size of sstable on disk |
| Total Size | Uncompressed size of data contained in the sstable |
| Min Timestamp | Minimum cell timestamp contained in the sstable |
| Max Timestamp | Maximum cell timestamp contained in the sstable |
| Duration | The time span between minimum and maximum cell timestamps |
| Min Deletion Time | The minimum deletion time |
| Max Deletion Time | The maximum deletion time |
| Level | Leveled Tiered Compaction sstable level |
| Keys | Number of partition keys |
| Avg Partition Size | Average partition size |
| Max Partition Size | Maximum partition size |
| Avg Column Count | Average number of columns in a partition |
| Max Column Count | Maximum number of columns in a partition |
| Droppable | Estimated droppable tombstones |
| Repaired At | Time when marked as repaired by incremental repair |
pstats
Tool for finding largest partitions. Reads the Index.db files so is relatively quick.
Usage
ic-sstable-tools pstats [-n <num>] [-t <snapshot>] [-f <filter>] <keyspace> <column-family>
| -h | Display help |
|---|---|
| -b | Batch mode. Uses progress indicator that is friendly for running in batch jobs. |
| -n |
Number of partitions to display |
| -t |
Snapshot to analyse. Snapshot is created if none is specified. |
| -f |
Comma separated list of Data.db sstables to filter on |
Output
Summary: Summary statistics about partitions
| Column | Description |
|---|---|
| Count (Size) | Number of partition keys on this node |
| Total (Size) | Total uncompressed size of all partitions on this node |
| Total (SSTable) | Number of sstables on this node |
| Minimum (Size) | Minimum uncompressed partition size |
| Minimum (SSTable) | Minimum number of sstables a partition belongs to |
| Average (Size) | Average (mean) uncompressed partition size |
| Average (SSTable) | Average (mean) number of sstables a partition belongs to |
| std dev. (Size) | Standard deviation of partition sizes |
| std dev. (SSTable) | Standard deviation of number of sstables for a partition |
| 50% (Size) | Estimated 50th percentile of partition sizes |
| 50% (SSTable) | Estimated 50th percentile of sstables for a partition |
| 75% (Size) | Estimated 75th percentile of partition sizes |
| 75% (SSTable) | Estimated 75th percentile of sstables for a partition |
| 90% (Size) | Estimated 90th percentile of partition sizes |
| 90% (SSTable) | Estimated 90th percentile of sstables for a partition |
| 95% (Size) | Estimated 95th percentile of partition sizes |
| 95% (SSTable) | Estimated 95th percentile of sstables for a partition |
| 99% (Size) | Estimated 99th percentile of partition sizes |
| 99% (SSTable) | Estimated 99th percentile of sstables for a partition |
| 99.9% (Size) | Estimated 99.9th percentile of partition sizes |
| 99.9% (SSTable) | Estimated 99.9th percentile of sstables for a partition |
| Maximum (Size) | Maximum uncompressed partition size |
| Maximum (SSTable) | Maximum number of sstables a partition belongs to |
Largest partitions: The top N largest partitions
| Column | Description |
|---|---|
| Key | The partition key |
| Size | Total uncompressed size of the partition |
| SSTable Count | Number of sstables that contain the partition |
SSTable Leaders: The top N partitions that belong to the most sstables
| Column | Description |
|---|---|
| Key | The partition key |
| SSTable Count | Number of sstables that contain the partition |
| Size | Total uncompressed size of the partition |
SSTables: Metadata about sstables as it relates to partitions.
| Column | Description |
|---|---|
| SSTable | Data.db filename of SSTable |
| Size | Uncompressed size |
| Min Timestamp | Minimum cell timestamp in the sstable |
| Max Timestamp | Maximum cell timestamp in the sstable |
| Level | Leveled Tiered Compaction level of sstable |
| Partitions | Number of partition keys in the sstable |
| Avg Partition Size | Average uncompressed partition size in sstable |
| Max Partition Size | Maximum uncompressed partition size in sstable |
cfstats
Tool for getting detailed cell statistics that can help identify issues with data model.
Usage
ic-sstable-tools cfstats [-n <num>] [-t <snapshot>] [-f <filter>] <keyspace> <column-family>
| -h | Display help |
|---|---|
| -b | Batch mode. Uses progress indicator that is friendly for running in batch jobs. |
| -n |
Number of partitions to display |
| -t |
Snapshot to analyse. Snapshot is created if none is specified. |
| -f |
Comma separated list of Data.db sstables to filter on |
Output
Summary: Summary statistics about partitions
| Column | Description |
|---|---|
| Count (Size) | Number of partition keys on this node |
| Rows (Size) | Number of clustering rows |
| (deleted) | Number of clustering row deletions |
| Total (Size) | Total uncompressed size of all partitions on this node |
| Total (SSTable) | Number of sstables on this node |
| Minimum (Size) | Minimum uncompressed partition size |
| Minimum (SSTable) | Minimum number of sstables a partition belongs to |
| Average (Size) | Average (mean) uncompressed partition size |
| Average (SSTable) | Average (mean) number of sstables a partition belongs to |
| std dev. (Size) | Standard deviation of partition sizes |
| std dev. (SSTable) | Standard deviation of number of sstables for a partition |
| 50% (Size) | Estimated 50th percentile of partition sizes |
| 50% (SSTable) | Estimated 50th percentile of sstables for a partition |
| 75% (Size) | Estimated 75th percentile of partition sizes |
| 75% (SSTable) | Estimated 75th percentile of sstables for a partition |
| 90% (Size) | Estimated 90th percentile of partition sizes |
| 90% (SSTable) | Estimated 90th percentile of sstables for a partition |
| 95% (Size) | Estimated 95th percentile of partition sizes |
| 95% (SSTable) | Estimated 95th percentile of sstables for a partition |
| 99% (Size) | Estimated 99th percentile of partition sizes |
| 99% (SSTable) | Estimated 99th percentile of sstables for a partition |
| 99.9% (Size) | Estimated 99.9th percentile of partition sizes |
| 99.9% (SSTable) | Estimated 99.9th percentile of sstables for a partition |
| Maximum (Size) | Maximum uncompressed partition size |
| Maximum (SSTable) | Maximum number of sstables a partition belongs to |
Row Histogram: Histogram of number of rows per partition
| Column | Description |
|---|---|
| Percentile | Minimum, average, standard deviation (std dev.), percentile, maximum |
| Count | Estimated number of rows per partition for the given percentile |
Largest partitions: Partitions with largest uncompressed size
| Column | Description |
|---|---|
| Key | The partition key |
| Size | Total uncompressed size of the partition |
| Rows | Total number of clustering rows in the partition |
| (deleted) | Number of row deletions in the partition |
| Tombstones | Number of cell or range tombstones |
| (droppable) | Number of tombstones that can be dropped as per gc_grace_seconds |
| Cells | Number of cells in the partition |
| SSTable Count | Number of sstables that contain the partition |
Widest partitions: Partitions with the most cells
| Column | Description |
|---|---|
| Key | The partition key |
| Rows | Total number of clustering rows in the partition |
| (deleted) | Number of row deletions in the partition |
| Cells | Number of cells in the partition |
| Tombstones | Number of cell or range tombstones |
| (droppable) | Number of tombstones that can be dropped as per gc_grace_seconds |
| Size | Total uncompressed size of the partition |
| SSTable Count | Number of sstables that contain the partition |
Most Deleted Rows: Partitions with the most row deletions
| Column | Description |
|---|---|
| Key | The partition key |
| Rows | Total number of clustering rows in the partition |
| (deleted) | Number of row deletions in the partition |
| Size | Total uncompressed size of the partition |
| SSTable Count | Number of sstables that contain the partition |
Tombstone Leaders: Partitions with the most tombstones
| Column | Description |
|---|---|
| Key | The partition key |
| Tombstones | Number of cell or range tombstones |
| (droppable) | Number of tombstones that can be dropped as per gc_grace_seconds |
| Rows | Total number of clustering rows in the partition |
| Cells | Number of cells in the partition |
| Size | Total uncompressed size of the partition |
| SSTable Count | Number of sstables that contain the partition |
SSTable Leaders: Partitions that are in the most sstables
| Column | Description |
|---|---|
| Key | The partition key |
| SSTable Count | Number of sstables that contain the partition |
| Size | Total uncompressed size of the partition |
| Rows | Total number of clustering rows in the partition |
| Cells | Number of cells in the partition |
| Tombstones | Number of cell or range tombstones |
| (droppable) | Number of tombstones that can be dropped as per gc_grace_seconds |
SSTables: Metadata about sstables as it relates to partitions.
| Column | Description |
|---|---|
| SSTable | Data.db filename of SSTable |
| Size | Uncompressed size |
| Min Timestamp | Minimum cell timestamp in the sstable |
| Max Timestamp | Maximum cell timestamp in the sstable |
| Partitions | Number of partitions |
| (deleted) | Number of row level partition deletions |
| (avg size) | Average uncompressed partition size in sstable |
| (max size) | Maximum uncompressed partition size in sstable |
| Rows | Total number of clustering rows in sstable |
| (deleted) | Number of row deletions in sstable |
| Cells | Number of cells in the SSTable |
| Tombstones | Number of cell or range tombstones in the SSTable |
| (droppable) | Number of tombstones that are droppable according to gc_grace_seconds |
| (range) | Number of range tombstones |
| Cell Liveness | Percentage of live cells. Does not consider tombstones or cell updates shadowing cells. That is it is percentage of non-tombstoned cells to total number of cells. |
purge
Finds the largest reclaimable partitions (GCable). Intensive process, effectively does "fake" compactions to calculate metrics.
Usage
ic-sstable-tools purge [-n <num>] [-t <snapshot>] [-f <filter>] <keyspace> <column-family>
| -h | Display help |
|---|---|
| -b | Batch mode. Uses progress indicator that is friendly for running in batch jobs. |
| -n |
Number of partitions to display |
| -t |
Snapshot to analyse. Snapshot is created if none is specified. |
Output
Largest reclaimable partitions: Partitions with the largest amount of reclaimable data
| Column | Description |
|---|---|
| Key | The partition key |
| Size | Total uncompressed size of the partition |
| Reclaim | Reclaimable uncompressed size |
| Generations | SSTable generations the partition belongs to |
Please see https://www.instaclustr.com/support/documentation/announcements/instaclustr-open-source-project-status/ for Instaclustr support status of this project
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