annotate doc/postgresql.txt @ 6565:2c2dbfc332ba

Try to handle multiple connections better. The session database is a hot spot. When multiple requests (e.g. 20) come in at the same time session database contention can get great. The original code didn't retry session database access when the open failed. This resulted in errors at the client. The second pass delayed 0.01 seconds and retried. It was better but we still had multiple second stalls. I think the first request got in, everybody else backed up and then retried at the same time. Again they stepped on each other. With logging I would see many counters go all the way to low single digits or to -1 indicating falure. This pass uses randomint to generate delays from 0-.125 seconds in 5ms increments. This performs better in testing. I rarely saw a counter less than 13 (2 failed retries). Current logging starts after 6 failures and counts down until success or failure.
author John Rouillard <rouilj@ieee.org>
date Thu, 16 Dec 2021 20:02:00 -0500
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1 .. index:: postgres; deployment notes
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3 ==========================
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4 PostgreSQL/psycopg Backend
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5 ==========================
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7 This are notes about PostqreSQL backend based on the psycopg adapter for
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8 Roundup issue tracker.
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10 Prerequisites
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11 =============
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13 To use PostgreSQL as backend for storing roundup data, you should
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14 additionally install:
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16 1. PostgreSQL 8.x or higher - https://www.postgresql.org/
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18 2. The psycopg python interface to PostgreSQL:
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20 https://www.psycopg.org/
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23 Running the PostgreSQL unit tests
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24 =================================
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26 The user that you're running the tests as will need to be able to access
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27 the postgresql database on the local machine and create and drop
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28 databases. See the config values in 'test/db_test_base.py'
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29 about which database connection, name and user will be used.
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32 Credit
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33 ======
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35 The postgresql backend was originally submitted by Federico Di Gregorio
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36 <fog@initd.org>
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37

Roundup Issue Tracker: http://roundup-tracker.org/