Overview

The purpose of this test report is to highlight results from mod-oai-pmh harvesting tests.

Test flow

Test consist of few calls:

Initial call:

/oai/records?verb=ListRecords&metadataPrefix=marc21_withholdings&apikey=[APIKey] - performing only once

Harvesting call:

/oai/records?verb=ListRecords&apikey=[APIKey]&resumptionToken=[resumptionToken] - performing cyclically until there is data in [tenant]_mod_oai_pmh.instances table to harvest.

[resumptionToken] returning in initial call response and in each harvesting call until there is something to harvest. When all data has being harvested - resumptionToken will not return with response.

Environment:

61 back-end modules deployed in 110 ECS services
3 okapi ECS services
8 m5.large EC2 instances
2 db.r5.xlarge AWS RDS instance (1 reader, 1 writer)

Software version

mod-oai-pmh 3.4.2

Summary

We're able to harvest all data set we have, which is 7.2 M records with different "Max records per response" parameter value.

Possibly there's a memory leak on oai-pmh side as we've seen continuously growing memory and CPU usage (see screenshots below).

Tests and results

test	Max records per response	Time to complete	Result	Issues
1	100	6 hours 26 minutes	all data harvested	Growing CPU/RAM usage
2	300	2 hours 31 min	5.5 M records harvested	connection lost with load generator not an oai-pmh issue
3	500	2 hour 27 min	all data harvested	Growing CPU/RAM usage

Service CPU usage

Service Memory usage

Source-record-storage memory usage

Source-record-storage CPU usage

Source-record-manager memory usage

Source-record-manager CPU usage

mod-inventory-storage CPU usage

mod-inventory-storage memory usage

Heap Analysis

There's 2 issues as a leak suspects common for each heap dumps taken (after each test):

io.vertx.core.http.impl.HttpClientImpl:

There is growing instances number 7 347 → 13 248 → 20 664;

io.vertx.core.http.impl.ConnectionManager:

There is growing instances number 14 694 →26 514 → 41 328;