[JAMES-3728] ElaticSearch race condition between email moves and flag changes

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.7.0
• Component/s: elasticsearch, mailbox
• Assignee: Unassigned
• Reporter: Benoit Tellier
• Created: 17/Mar/22 04:45
• Updated: 13/Sep/23 14:22

Description

Description

We are writting a JMAP client app called TMail written in FLutter.

In the sent mailbox we noticed the following behaviour:

Request

{
    "using": [
        "urn:ietf:params:jmap:core",
        "urn:ietf:params:jmap:mail"
    ],
    "methodCalls": [
        [
            "Email/query",
            {
                "accountId": "{{accountId}}",
                "limit": 20,
                "filter": {
                    "inMailbox": "{{Sent}}",
                    "notKeyword": "$seen"
                },
                "sort": [{
                  "property":"sentAt",
                  "isAscending": false
                }],
                "position": 0
            },
            "c2"
        ],
        [
            "Email/get",
            {
                "accountId": "{{accountId}}",
                "properties": [
                    "subject",
                    "from",
                    "receivedAt",
                    "sentAt",
                    "preview",
                    "hasAttachment",
                    "mailboxIds",
                    "keywords"
                ],
                "#ids": {
                    "resultOf": "c2",
                    "name": "Email/query",
                    "path": "ids/*"
                }
            },
            "c3"
        ]
    ]
}

Response

{
    "sessionState": "2c9f1b12-b35a-43e6-9af2-0106fb53a943",
    "methodResponses": [
        [
            "Email/query",
            {
                "accountId": "3ce33c876a726662c627746eb9537a1d13c2338193ef27bd051a3ce5c0fe5b12",
                "queryState": "11dc2cfd",
                "canCalculateChanges": false,
                "ids": [
                    "c331d3c0-90ac-11ec-984e-e3f8b83572b4",
                    "36128e70-32e8-11ec-a759-2fef1ee78d9e",
                    "4b0db860-32e6-11ec-a759-2fef1ee78d9e",
                    "4f769140-2cc6-11ec-a759-2fef1ee78d9e",
                    "3b21cb60-2cc6-11ec-a759-2fef1ee78d9e",
                    "254999d0-2cc6-11ec-a759-2fef1ee78d9e",
                    "19707570-2cc6-11ec-a759-2fef1ee78d9e",
                    "0e877d70-2cc6-11ec-a759-2fef1ee78d9e",
                    "8b5a5280-2cc3-11ec-a759-2fef1ee78d9e",
                    "826ba3e0-2cc3-11ec-a759-2fef1ee78d9e",
                    "5f771f90-2cc3-11ec-a759-2fef1ee78d9e"
                ],
                "position": 0
            },
            "c2"
        ],
        [
            "Email/get",
            {
                "accountId": "3ce33c876a726662c627746eb9537a1d13c2338193ef27bd051a3ce5c0fe5b12",
                "notFound": [],
                "state": "c55b33d0-a52e-11ec-90ba-e169393c493e",
                "list": [
                    {
                        "preview": "------- Forwarded message ------- Subject: [linshare-mobile-flutter-app-android-release] - Build [success] Date: October 8, 2021 12:50 PM From: [e-mail] To: [e-mail] <[e-mail]>, [e-mail] <[e-mail]-paa",
                        "hasAttachment": false,
                        "keywords": {
                            "$seen": true
                        },
                        "subject": "Fwd: [linshare-mobile-flutter-app-android-release] - Build [success]",
                        "mailboxIds": {
                            "abb99c10-18d9-11eb-a677-2990b970028d": true
                        },
                        "from": [
                            {
                                "name": "Lê Nguyễn User B",
                                "email": "[e-mail]"
                            }
                        ],
                        "sentAt": "2021-10-14T07:51:15Z",
                        "id": "826ba3e0-2cc3-11ec-a759-2fef1ee78d9e",
                        "receivedAt": "2021-10-14T07:51:15Z"
                    },
 ....

As we can see, `Email/query` and `Email/get` disagrees on wether the message is seen or not!

This happens primarily in the Sent mailbox.

Explanation ?

Email/query relies on elasticSearch while Email/get relies on cassandra. Getting those two in sync can be an issue and you can have inconsistencies across the 2 data-stores. Now the indexing is done asynchronously which means that if two actions happens veeeery quickly (say read then move emails or vice versa) we can get into a data race in elasticsearch where we do the operation in the wrong order which could result into what you actually see.

Moving emails to sent box does just that: mark as seen and move in one request

To be very techish our event system don't guaranty ordering, and the underlying operation don't commute.

Ordering don't seem achievable on RabbitMQ (contrary to Pulsar/Kafka)

Working on commutativity can likely help!

Fix?

I got an idea of a fix. Basically the key problem is that we use a mutable id as an indexing key which results in poor, non transactional behaviour if indexing requests get reordered. Of course it demands significant redesign of ES layers... And might bring additional concerns!

Original report from Dat Pham Hoang

https://github.com/linagora/tmail-flutter/issues/340#issuecomment-1069188877