perf: Add connection pool to configure connection lifecycle.

[tristanvuong2021]

The pool will close connections that are idle for too long.

[wfa-reviewable]

This change is 

[SanjayVas]

Reviewed 4 of 5 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @tristanvuong2021)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresConnectionFactories.kt line 38 at r2 (raw file):

          .option(ConnectionFactoryOptions.DATABASE, flags.database)
          .option(ConnectionFactoryOptions.HOST, flags.cloudSqlInstance)
          .option(ConnectionFactoryOptions.STATEMENT_TIMEOUT, Duration.ofSeconds(120))

Have all of these values come from flags.

[tristanvuong2021]

Reviewable status: 4 of 6 files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

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src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresConnectionFactories.kt line 38 at r2 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

Have all of these values come from flags.

Done.

[SanjayVas]

Reviewed 2 of 2 files at r3, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @tristanvuong2021)

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src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 50 at r3 (raw file):

    required = false,
  )
  var statementTimeoutSeconds: Long = 120

Use Duration for these

Suggestion:

    names = ["--statement-timeout"],
    description = ["Statement timeout"],
    required = false,
    defaultValue = "120s",
  )
  lateinit var statementTimeout: Duration

[tristanvuong2021]

Reviewable status: 4 of 6 files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 50 at r3 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

Use Duration for these

Done.

[SanjayVas]

Reviewed 4 of 4 files at r4, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @tristanvuong2021)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 51 at r4 (raw file):

    required = false,
  )
  var statementTimeout: Duration = Duration.ofSeconds(120)

Don't assign the default in Kotlin. Make these lateinit vars and use defaultValue from the Option annotation

Code quote:

= Duration.ofSeconds(120)

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src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 55 at r4 (raw file):

  @CommandLine.Option(
    names = ["--max-idle-time-minutes"],

Suggestion:

--max-idle-time

[tristanvuong2021]

Reviewable status: 5 of 6 files reviewed, 2 unresolved discussions (waiting on @SanjayVas)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 51 at r4 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

Don't assign the default in Kotlin. Make these lateinit vars and use defaultValue from the Option annotation

Done.

[tristanvuong2021]

Reviewable status: 5 of 6 files reviewed, 2 unresolved discussions (waiting on @SanjayVas)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 55 at r4 (raw file):

  @CommandLine.Option(
    names = ["--max-idle-time-minutes"],

Done.

[SanjayVas]

Reviewed all commit messages.
Reviewable status: 5 of 6 files reviewed, 1 unresolved discussion (waiting on @tristanvuong2021)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 50 at r5 (raw file):

    description = ["Statement timeout duration."],
    required = false,
    defaultValue = "PT120S",

This should be using human readable durations. I've stated in a previous PR that org.wfanet.measurement.common.DurationFormat shouldn't exist and it should always use the human-readable format, i.e. that #174 should never have been merged.

Suggestion:

120s

[tristanvuong2021]

Reviewable status: 5 of 6 files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 50 at r5 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

This should be using human readable durations. I've stated in a previous PR that org.wfanet.measurement.common.DurationFormat shouldn't exist and it should always use the human-readable format, i.e. that #174 should never have been merged.

Done.

[SanjayVas]

Reviewed 1 of 1 files at r6, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @tristanvuong2021)

---

src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 69 at r6 (raw file):

    required = false,
  )
  var maxPoolSize: Int = 16

Same here re: not setting defaults in Kotlin when they can be set using defaultValue

Suggestion:

var maxPoolSize by Delegates.notNull<Int>()

[tristanvuong2021]

Reviewable status: 5 of 6 files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

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src/main/kotlin/org/wfanet/measurement/gcloud/postgres/PostgresFlags.kt line 69 at r6 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

Same here re: not setting defaults in Kotlin when they can be set using defaultValue

Done.

[SanjayVas]

Reviewed 1 of 1 files at r7, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @stevenwarejones)

[stevenwarejones]

Reviewed 2 of 5 files at r1, 3 of 4 files at r4, 1 of 1 files at r7, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @tristanvuong2021)