seella

A tool for visualising the traces emitted by ScyllaDB.

Generates waterfall charts and a tree diagram of system_tracing.events in your terminal.

Basic invocation:

```text ❯ seella 74ff67c0-397b-11ee-8ca4-9688db6cc0f1

Session ID: 74ff67c0-397b-11ee-8ca4-9688db6cc0f1 2023-08-13T01:48:10.172+00:00 172.17.0.2 (anonymous) -> 172.17.0.2 Request Size: 84 Response Size: 20 Execute CQL3 query "{'consistencylevel': 'ONE', 'pagesize': '100', 'query': 'INSERT INTO k.t (pk, t, v, s) VALUES (0, 1, ''val1'', ''static1'');', 'serialconsistencylevel': 'SERIAL', 'user_timestamp': '1691891290172041'}"

waterfall chart dur node activity 1 [█─────┤ ] 0 172.17.0.2 ├┬─ Parsing a statement 2 [█ ] 5 172.17.0.3 │├─ Message received from /172.17.0.2 3 [███ ] 55 172.17.0.3 │├─ Sending mutation_done to /172.17.0.2 4 [ ████ ] 58 172.17.0.3 │├─ Mutation handling is done 5 [ █ ] 27 172.17.0.2 ├── Processing a statement 6 [ ███ ] 45 172.17.0.2 ├── Creating write handler for token: -3485513579396041028 natural: {172.17.0.3} pending: {} 7 [ ███ ] 46 172.17.0.2 ├── Creating write handler with live: {172.17.0.3} dead: {} 8 [ ███ ] 49 172.17.0.2 ├── Sending a mutation to /172.17.0.3 9 [ ████████████████████ ] 332 172.17.0.2 ├── Got a response from /172.17.0.3 10 [ █████████████████████ ] 333 172.17.0.2 ├── Delay decision due to throttling: do not delay, resuming now 11 [ ████████████████████ ] 339 172.17.0.2 ├── Mutation successfully completed 12 [ ██████████████████████] 344 172.17.0.2 ├── Done processing - preparing a result ```

Or one with more options:

```text ❯ seella -w 50 --show-event-id --show-span-ids --show-thread --max-activity-width 50 74ff67c0-397b-11ee-8ca4-9688db6cc0f1

waterfall chart dur node activity event id span id parent span id thread name 1 [█─┤ ] 0 172.17.0.2 ├┬─ Parsing a statement 74ff70c8-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 2 [█ ] 5 172.17.0.3 │├─ Message received from /172.17.0.2 74ff75b2-397b-11ee-a288-20cc230d8ac0 343569500103777 153249663699531 shard 4 3 [█ ] 55 172.17.0.3 │├─ Sending mutation_done to /172.17.0.2 74ff779d-397b-11ee-a288-20cc230d8ac0 343569500103777 153249663699531 shard 4 4 [ ██ ] 58 172.17.0.3 │├─ Mutation handling is done 74ff77c2-397b-11ee-a288-20cc230d8ac0 343569500103777 153249663699531 shard 4 5 [ █ ] 27 172.17.0.2 ├── Processing a statement 74ff71dc-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 6 [ █ ] 45 172.17.0.2 ├── Creating write handler for token: -348551357939604 74ff728a-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 7 [ ██ ] 46 172.17.0.2 ├── Creating write handler with live: {172.17.0.3} dea 74ff7296-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 8 [ █ ] 49 172.17.0.2 ├── Sending a mutation to /172.17.0.3 74ff72b1-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 9 [ ██████████ ] 332 172.17.0.2 ├── Got a response from /172.17.0.3 74ff7dc2-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 10 [ ███████████ ] 333 172.17.0.2 ├── Delay decision due to throttling: do not delay, re 74ff7dcb-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 11 [ ██████████ ] 339 172.17.0.2 ├── Mutation successfully completed 74ff7e09-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 12 [ ███████████] 344 172.17.0.2 ├── Done processing - preparing a result 74ff7e3a-397b-11ee-8ca4-9688db6cc0f1 153249663699531 0 shard 0 ```

Usage

See seella --help for all the options:

```text A tool for visualising the traces emitted by ScyllaDB

Usage: seella [OPTIONS]

Arguments: The session id to be visualised

Options: -s, --sessions-path Path to the CSV containing the sessions data. Any string that can be coerced into a PathBuf [default: sessions.csv] -e, --events-path Path to the CSV containing the events data. Any string that can be coerced into a PathBuf [default: events.csv] -w, --waterfall-width The width of the waterfall chart [default: 100] -d, --duration-format Whether to generate span durations in milliseconds or microseconds [default: micros] [possible values: millis, micros] --min-duration-width Minimum print width for the duration field, remaining will be filled with spaces [default: 6] --max-activity-width Maximum print width for the activity field, remaining will be truncated [default: 300] --show-event-id Whether to show the event uuid --show-span-ids Whether to show the span ids --show-thread Whether to show the thread name -h, --help Print help -V, --version Print version ```

Samples

Run the following:

shell docker run --volume .:/data --name some-scylla --hostname some-scylla -d scylladb/scylla --smp 1 docker run --name some-scylla2 --hostname some-scylla2 -d scylladb/scylla --seeds="$(docker inspect --format='{{ .NetworkSettings.IPAddress }}' some-scylla)" docker exec -it some-scylla cqlsh

And then within that cqlsh session:

```sql TRACING ON;

CREATE KEYSPACE k WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'datacenter1' : 1 };

CREATE TABLE k.t ( pk int, t int, v text, s text static, PRIMARY KEY (pk, t) );

INSERT INTO k.t (pk, t, v, s) VALUES (0, 0, 'val0', 'static0'); INSERT INTO k.t (pk, t, v, s) VALUES (0, 1, 'val1', 'static1');

SELECT * FROM k.t;

COPY systemtraces.sessions TO '/data/sessions.csv' WITH HEADER = TRUE; COPY systemtraces.events TO '/data/events.csv' WITH HEADER = TRUE; ```

You will now have a sessions.csv and events.csv in your local directory that you can experiment with.