[PMM-9829] mongodb_exporter does not get collstats and indexstats metrics on default ASC and DESC index creation - Percona JIRA

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Details

Type: Bug
Status: Done
Priority: Medium
Resolution: Fixed
Affects Version/s: 2.26.0
Fix Version/s: 2.27.0
Component/s: MongoDB_Exporter
Labels:
None

Story Points:
1
Needs Review:
Yes
Needs QA:
Yes
Needs Doc:
Yes
Platform Team:
C/S Core

Description

Current scenario:

When querying what metrics can we get from this mongodb_exporter by using "curl http://pmm:[email protected]:<port>/metrics" we get the following error if there is a default ascending and descending index on collection.

'curl: (52) Empty reply from server' message.'

Test case:

Either pmm-admin and pmm-server on 2.26:

shell> pmm-admin --version
ProjectName: pmm-admin
Version: 2.26.0
PMMVersion: 2.26.0
Timestamp: 2022-02-03 14:03:35 (UTC)
FullCommit: ae906c7ade001878ba229a3452abc7ea8648fb97

shell>  docker exec -it pmm-server curl -ku admin:admin https://localhost/v1/version
{
 "version": "2.26.0",
 "server": {
 "version": "2.26.0",
 "full_version": "2.26.0-17.2202021129.6914083.el7",
 "timestamp": "2022-02-02T11:30:45Z"
 },

1. Added the Mongodb service using the following parameters:

shell> pmm-admin add mongodb --username=admin --password=sekret --tls-skip-verify --service-name=mongodb1-db --host=localhost --port=4410 --cluster=DES02 --replication-set=replset --environment=dev --query-source=profiler --enable-all-collectors --agent-password=pmm --max-collections-limit=0

shell> ps -aux | grep mongodb_exporter
root     1000594  6.4  0.0 722524 23536 ?        Sl   16:58   0:38 /usr/local/percona/pmm2/exporters/mongodb_exporter --collector.collstats --collector.collstats-limit=0 --collector.dbstats --collector.diagnosticdata --collector.indexstats --collector.replicasetstatus --collector.topmetrics --compatible-mode --discovering-mode --mongodb.global-conn-pool --web.listen-address=:42004
root     1009975  0.0  0.0   9052  2628 pts/0    S+   17:08   0:00 grep --color=auto mongodb_exporter

2. Then, created a fake collection and inserted a few documents:

replset:PRIMARY> db.CS0025955.find()
{ "_id" : ObjectId("6251e6d8f5254aadb1464c44"), "c32" : 0, "last_modified" : ISODate("2022-04-09T20:04:40.269Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c45"), "c32" : 1, "last_modified" : ISODate("2022-04-09T20:04:40.299Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c46"), "c32" : 2, "last_modified" : ISODate("2022-04-09T20:04:40.302Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c47"), "c32" : 3, "last_modified" : ISODate("2022-04-09T20:04:40.304Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c48"), "c32" : 4, "last_modified" : ISODate("2022-04-09T20:04:40.307Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c49"), "c32" : 5, "last_modified" : ISODate("2022-04-09T20:04:40.309Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4a"), "c32" : 6, "last_modified" : ISODate("2022-04-09T20:04:40.311Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4b"), "c32" : 7, "last_modified" : ISODate("2022-04-09T20:04:40.313Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4c"), "c32" : 8, "last_modified" : ISODate("2022-04-09T20:04:40.315Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4d"), "c32" : 9, "last_modified" : ISODate("2022-04-09T20:04:40.318Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4e"), "c32" : 10, "last_modified" : ISODate("2022-04-09T20:04:40.320Z") }
{ "_id" : ObjectId("6251e6d8f5254aadb1464c4f"), "c32" : 11, "last_modified" : ISODate("2022-04-09T20:04:40.323Z") }

3. After that, the following index structure was deployed:

replset:PRIMARY>db.CS0025955.createIndex({"c32":1})
replset:PRIMARY>db.CS0025955.createIndex({"c32":-1})

[
 {
  "v" : 2,
  "key" : {
   "_id" : 1
  },
  "name" : "_id_"
 },
 {
  "v" : 2,
  "key" : {
   "c32" : 1
  },
  "name" : "c32_1"
 },
 {
  "v" : 2,
  "key" : {
   "c32" : -1
  },
  "name" : "c32_-1"
 }
]

4. The next step was to validate the metrics gathering via the curl command:

shell> curl -i http://pmm:[email protected]:42004/metrics
curl: (52) Empty reply from server

**Extra test/scenarios:

1. Dropping only the ascending index:

replset:PRIMARY> db.CS0025955.dropIndex("c32_1")
{
 "nIndexesWas" : 3,
 "ok" : 1,

shell> curl -i http://pmm:[email protected]:42004/metrics | grep access
# TYPE mongodb_CS0026174_person_id_accesses_ops untyped
mongodb_CS0026174_person_id_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="_id_",namespace="CS0026174.person",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_CS0025955_c32_1_accesses_ops percona_CS0025955_c32_-1.accesses.
# TYPE mongodb_percona_CS0025955_c32_1_accesses_ops untyped
mongodb_percona_CS0025955_c32_1_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="c32_-1",namespace="percona.CS0025955",rs_nm="replset",rs_state="1"} 0 # HELP mongodb_percona_CS0025955_id_accesses_ops percona_CS0025955__id_.accesses.
# TYPE mongodb_percona_CS0025955_id_accesses_ops untyped

Worked

2. Recreating the ascending and dropping only the descending index:

replset:PRIMARY> db.CS0025955.dropIndex("c32_-1")
{
 "nIndexesWas" : 3,
 "ok" : 1,

shell> curl -i http://pmm:[email protected]:42004/metrics | grep access


# HELP mongodb_CS0026174_person_id_accesses_ops CS0026174_person__id_.accesses.
# TYPE mongodb_CS0026174_person_id_accesses_ops untyped
mongodb_CS0026174_person_id_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="_id_",namespace="CS0026174.person",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_CS0025955_c32_1_accesses_ops percona_CS0025955_c32_1.accesses.
# TYPE mongodb_percona_CS0025955_c32_1_accesses_ops untyped
mongodb_percona_CS0025955_c32_1_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="c32_1",namespace="percona.CS0025955",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_CS0025955_id_accesses_ops percona_CS0025955__id_.accesses.
# TYPE mongodb_percona_CS0025955_id_accesses_ops untyped

Worked.

4. Using a different collection structure but creating the default ascending and descending indexes:

--- collection sample --
{ "_id" : ObjectId("6228eb907e86f06c7d180387"), "field1" : 951, "field2" : 0.5993044711817684, "field3" : "d9168548d905466364a81c1d1520c1e9" }
{ "_id" : ObjectId("6228eb907e86f06c7d180224"), "field1" : 596, "field2" : 0.11354347580806556, "field3" : "1b6fc233e1cb062ccff127739e70fd55" }
{ "_id" : ObjectId("6228eb8f7e86f06c7d1800f6"), "field1" : 294, "field2" : 0.10073154000241427, "field3" : "d8b5427bbf24e374231fea4838410c74" }
{ "_id" : ObjectId("6228eb907e86f06c7d18037e"), "field1" : 942, "field2" : 0.7222825020150281, "field3" : "c29b50c6bbf5d3f247894509aaa928c1" }
{ "_id" : ObjectId("6228eb907e86f06c7d18024e"), "field1" : 638, "field2" : 0.45752419257402827, "field3" : "f9281fa70be559d48592a520fe728c1c" }

--- index structure ---
 {
  "v" : 2,
  "key" : {
   "field3" : 1
  },
  "name" : "field3_1"
 },
 {
  "v" : 2,
  "key" : {
   "field3" : -1
  },
  "name" : "field3_-1"
 }

4.1. Then:

shell> curl -i http://pmm:[email protected]:42004/metrics | grep access
curl: (52) Empty reply from server

Not Worked.

5. But, creating the same ascending and descending index, but with non-default names:

{
  "v" : 2,
  "key" : {
   "field3" : 1
  },
"name" : "ascending"
 },
 {
  "v" : 2,
  "key" : {
   "field3" : -1
  },
"name" : "descending"
}

shell> curl -i http://pmm:[email protected]:42004/metrics | grep access
# HELP mongodb_CS0026174_person_id_accesses_ops CS0026174_person__id_.accesses.
# TYPE mongodb_CS0026174_person_id_accesses_ops untyped
mongodb_CS0026174_person_id_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="_id_",namespace="CS0026174.person",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_date_id_accesses_ops percona_date__id_.accesses.
# TYPE mongodb_percona_date_id_accesses_ops untyped
mongodb_percona_date_id_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="_id_",namespace="percona.date",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_tagTest_id_accesses_ops percona_tagTest__id_.accesses.
[...]
mongodb_percona_test_collection_ascending_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="ascending",namespace="percona.test_collection",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_test_collection_descending_accesses_ops percona_test_collection_descending.accesses.
# TYPE mongodb_percona_test_collection_descending_accesses_ops untyped
mongodb_percona_test_collection_descending_accesses_ops{cl_id="619bfecfd077ff94db2b1ee7",cl_role="",key_name="descending",namespace="percona.test_collection",rs_nm="replset",rs_state="1"} 0
# HELP mongodb_percona_test_collection_id_accesses_ops percona_test_collection__id_.accesses.
# TYPE mongodb_percona_test_collection_id_accesses_ops untyped

It Worked.

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People

Assignee:: Shashank Sinha (Inactive)

Reporter:: Jean Nunes da Silva

Votes:: 0 Vote for this issue

Watchers:: 5 Start watching this issue

Dates

Created:: 09/Apr/22 9:13 PM

Updated:: 28/Jun/22 1:55 PM

Resolved:: 03/May/22 8:25 AM