Howto reduce disk io on a Synology Docker InfluxDB

InfluxDB 1
,
1

Hello Forum

I’m running an InfluxDB 1.8.9 OSS in a Docker container on an SYNOLOGY DS1522+ NAS using DSM 7.1.

I found very high disk write rates of abt. 2MBytes/s when inserting measurements with two tags and one value.
I’m using the “influxdb out” node in Node-RED v2.2.3 to write with a rate of about 5 measurements per second.

Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
sata2           141.00         0.00      2325.00         0.00          0       2325          0

Logging ist turned off via

  • INFLUXDB_REPORTING_DISABLED = true
  • INFLUXDB_HTTP_LOG_ENABLED = false
  • INFLUXDB_QUERY_LOG_ENABLED = false

And I’ve set INFLUXDB_DATA_WAL_FSYNC_DELAY to 1s

Any ideas what I’m doing wrong and how I can reduce disk io?

Thanks in advance

Dietmar

2

Hello @DietmarK,
Thats very odd. How many points are in each measurement?

3

@Anaisdg

Thanks for coming back to my question!

Sorry, I’m not quite up to speed with the terms - exactly one “datapoint” is always inserted. The measurement has two numerical tags and the numerical measurement value.

The conf file is more or less empty:

[meta]
  dir = "/var/lib/influxdb/meta"

[data]
  dir = "/var/lib/influxdb/data"
  engine = "tsm1"
  wal-dir = "/var/lib/influxdb/wal"

Did I miss something important?

Thanks

//Dietmar

4

is it possible that these setting can cause this high workload on each insert?

CREATE RETENTION POLICY "rp_1w"      ON "high_volume" DURATION 1w REPLICATION 1 DEFAULT 
CREATE RETENTION POLICY "rp_forever" ON "high_volume" DURATION INF REPLICATION 1 
CREATE CONTINUOUS QUERY "cq_5min"    ON "high_volume" BEGIN SELECT mean(value) AS mean_value, max(value) AS max_value, min(value) AS min_value INTO "high_volume"."rp_forever"."sensors" FROM "high_volume"."rp_1w"."sensors" GROUP BY time(5m), * END

Thanks

//Dietmar

5

Hm, I’ve removed the CQ and still same load - any more ideas?

6

It is getting more strange - on a RaspberryPi docker image with InfluxDB 1.8.4 with the same settings and influxdb.conf I get IO rates with 50kBytes/s

HELP!!!