Re: How different is AWS-RDS postgres?

Rob Sargent <robjsargent@gmail.com>

From: Rob Sargent <robjsargent@gmail.com>
To: Sam Gendler <sgendler@ideasculptor.com>
Cc: Philip Semanchuk <philip@americanefficient.com>, Ian Harding <harding.ian@gmail.com>, Ron <ronljohnsonjr@gmail.com>, "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
Date: 2021-05-27T21:58:24Z
Lists: pgsql-general
On 5/27/21 3:08 PM, Sam Gendler wrote:
> The same JDBC connection that is resulting in lost data?  Sounds to me 
> like you aren't connecting to the DB you think you are connecting to.
>
I almost wish that were true.

However, looking at AWS "Performance Insights" is see the sql statements 
generate by my app begin executed on the server.  Not coincidentally 
this is from the "Top SQL (10)/Load by waits" view. Now that view does 
NOT, in point of fact, name the database in which the sql is running, 
but the rest of my environment pretty much rules out silently switching 
tracks on myself.  I have to read from the correct database, using a 
UUID, to get data to analyze, then save the results of the analysis 
back. I'm using my wonderful webapp to run this and I've successfully 
analyzed and stored result for small starting data sets.

I just notice the "Top database" tab on that screen:  there is only one 
and it's the correct one.

I've reproduced the behaviour.  I'm pretty convinced it a size thing, 
but which part of the system is being max'd out is not clear.  Not CPU, 
but that's the only resource the "Performance Insight" mentions 
(suggesting this UI wasn't designed by a database person).

The loss of the staging table is most spectacular.  It filled from a 
file which has 7.5M records. It's clear in the tomcat logs that is was 
created and written to, one record read.  Then the "top sql" happens:

    insert into segment select * from
    bulk."rjs_GEV15_01_c9e224ca_85d2_40b4_ad46_327cfb9f0ac6" as s where
    s.probandset_id >= ? and s.probandset_id < ?

the "bulk" table is the staging table. The params are filled in with a 
quasi-uuid which grab roughly 1/16th of the data.  In the stack trace on 
my tomcat server I get

    Caused by: org.jooq.exception.DataAccessException: SQL [insert into
    segment select * from
    bulk."rjs_GEV15_01_c9e224ca_85d2_40b4_ad46_327cfb9f0ac6" as s where 
    s.probandset_id >= '30000000-0000-0000-0000-00000000\
    0000' and s.probandset_id < '40000000-0000-0000-0000-000000000000'
    ]; An I/O error occurred while sending to the backend.

So this would have been the fourth such insert statement read from that 
staging table.

That table is not deleted by my code.  It is renamed after the last 
insert into segment, by appending "_done" to the name.  But that table, 
by either name, is nowhere to be seen on the server.

For those scoring at home, the trouble in the tomcat log start with

    0:02:11.452 [https-jsse-nio-10.0.2.28-15002-exec-7] INFO
    edu.utah.camplab.jx.PayloadFromMux -
    bulk."rjs_GEV15_01_c9e224ca_85d2_40b4_ad46_327cfb9f0ac6": Begin
    transfer from bulk to segment
    27-May-2021 20:02:50.338 FINE [Catalina-utility-2]
    org.apache.catalina.session.ManagerBase.processExpires Start expire
    sessions StandardManager at 1622145770338 sessioncount 0
    27-May-2021 20:02:50.338 FINE [Catalina-utility-2]
    org.apache.catalina.session.ManagerBase.processExpires End expire
    sessions StandardManager processingTime 0 expired sessions: 0
    27-May-2021 20:02:50.476 FINE [Catalina-utility-2]
    org.apache.catalina.session.ManagerBase.processExpires Start expire
    sessions StandardManager at 1622145770476 sessioncount 1
    27-May-2021 20:02:50.476 FINE [Catalina-utility-2]
    org.apache.catalina.session.ManagerBase.processExpires End expire
    sessions StandardManager processingTime 0 expired sessions: 0
    27-May-2021 20:02:51.847 WARNING [Tomcat JDBC Pool
    Cleaner[1731185718:1622133381802]]
    org.apache.tomcat.jdbc.pool.ConnectionPool.abandon Connection has
    been abandoned PooledConnection[org.postgresql.jdbc.PgCo\
    nnection@1622ead9]:java.lang.Exception
             at
    org.apache.tomcat.jdbc.pool.ConnectionPool.getThreadDump(ConnectionPool.java:1163)
             at
    org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:816)
             at
    org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:660)
             at
    org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:198)
             at
    org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:132)
             at
    org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:90)
             at
    edu.utah.camplab.servlet.AbstractSGSServlet.getDbConn(AbstractSGSServlet.java:123)
             at
    edu.utah.camplab.servlet.AbstractSGSServlet.getDbConn(AbstractSGSServlet.java:105)
             at
    edu.utah.camplab.servlet.PayloadSaveServlet.doPost(PayloadSaveServlet.java:50)
    ....
    20:02:51.854 [https-jsse-nio-10.0.2.28-15002-exec-7] DEBUG
    org.jooq.impl.DefaultConnectionProvider - rollback to savepoint
    20:02:51.855 [https-jsse-nio-10.0.2.28-15002-exec-7] DEBUG
    org.jooq.impl.DefaultConnectionProvider - rollback
    20:02:51.855 [https-jsse-nio-10.0.2.28-15002-exec-7] DEBUG
    org.jooq.impl.DefaultConnectionProvider - setting auto commit : true
    20:02:51.855 [https-jsse-nio-10.0.2.28-15002-exec-7] ERROR
    edu.utah.camplab.jx.AbstractPayload - run
    c9e224ca-85d2-40b4-ad46-327cfb9f0ac6: Exception from db write: SQL
    [insert into segment select * from bulk.\
    "rjs_GEV15_01_c9e224ca_85d2_40b4_ad46_327cfb9f0ac6" as s where
    s.probandset_id >= '30000000-0000-0000-0000-000000000000' and
    s.probandset_id < '40000000-0000-0000-0000-000000000000' ]; An I/O
    error occurred \
    while sending to the backend.: {}
    org.jooq.exception.DataAccessException: SQL [insert into segment
    select * from
    bulk."rjs_GEV15_01_c9e224ca_85d2_40b4_ad46_327cfb9f0ac6" as s where 
    s.probandset_id >= '30000000-0000-0000-0000-000000000000' an\
    d s.probandset_id < '40000000-0000-0000-0000-000000000000' ]; An I/O
    error occurred while sending to the backend.
             at org.jooq_3.14.7.POSTGRES.debug(Unknown Source)
             at org.jooq.impl.Tools.translate(Tools.java:2880)
             at
    org.jooq.impl.DefaultExecuteContext.sqlException(DefaultExecuteContext.java:757)
             at org.jooq.impl.AbstractQuery.execute(AbstractQuery.java:389)
             at
    edu.utah.camplab.jx.PayloadFromMux.insertAllSegments(PayloadFromMux.java:177)
             at
    edu.utah.camplab.jx.PayloadFromMux.lambda$completeSegmentSave$3(PayloadFromMux.java:165)
             at
    org.jooq.impl.DefaultDSLContext$3.run(DefaultDSLContext.java:615)
             at
    org.jooq.impl.DefaultDSLContext$3.run(DefaultDSLContext.java:612)
             at
    org.jooq.impl.DefaultDSLContext.lambda$transactionResult0$0(DefaultDSLContext.java:543)
             at org.jooq.impl.Tools$35$1.block(Tools.java:5203)
             at
    java.base/java.util.concurrent.ForkJoinPool.managedBlock(ForkJoinPool.java:3137)
             at org.jooq.impl.Tools$35.get(Tools.java:5200)
             at
    org.jooq.impl.DefaultDSLContext.transactionResult0(DefaultDSLContext.java:595)
             at
    org.jooq.impl.DefaultDSLContext.transactionResult(DefaultDSLContext.java:512)
             at
    org.jooq.impl.DefaultDSLContext.transaction(DefaultDSLContext.java:612)
             at
    edu.utah.camplab.jx.PayloadFromMux.completeSegmentSave(PayloadFromMux.java:164)
             at
    edu.utah.camplab.jx.PayloadFromMux.writedb(PayloadFromMux.java:45)
             at
    edu.utah.camplab.jx.AbstractPayload.lambda$write$0(AbstractPayload.java:77)
             at
    org.jooq.impl.DefaultDSLContext$3.run(DefaultDSLContext.java:615)

    ...
            Suppressed: org.jooq.exception.DataAccessException: Cannot
    rollback transaction
                     at
    org.jooq.impl.DefaultConnectionProvider.rollback(DefaultConnectionProvider.java:142)
                     at
    org.jooq.impl.DefaultTransactionProvider.rollback(DefaultTransactionProvider.java:223)
                     at
    org.jooq.impl.DefaultDSLContext.lambda$transactionResult0$0(DefaultDSLContext.java:567)
                     ... 45 common frames omitted
             Caused by: java.sql.SQLException: Connection has already
    been closed.
                     at
    org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:117)
                     at
    org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
                     at
    org.apache.tomcat.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:79)
                     at
    org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
                     at
    org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81)
                     at com.sun.proxy.$Proxy4.rollback(Unknown Source)
                     at
    org.jooq.impl.DefaultConnectionProvider.rollback(DefaultConnectionProvider.java:139)
                     ... 47 common frames omitted
             Suppressed: org.jooq.exception.DataAccessException: Cannot
    set autoCommit
                     at
    org.jooq.impl.DefaultConnectionProvider.setAutoCommit(DefaultConnectionProvider.java:222)
                     at
    org.jooq.impl.DefaultTransactionProvider.brace(DefaultTransactionProvider.java:246)
                     at
    org.jooq.impl.DefaultTransactionProvider.rollback(DefaultTransactionProvider.java:229)
                     at
    org.jooq.impl.DefaultDSLContext.lambda$transactionResult0$0(DefaultDSLContext.java:567)
                     ... 33 common frames omitted
             Caused by: java.sql.SQLException: Connection has already
    been closed.
                     at
    org.apache.tomcat.jdbc.pool.ProxyConnection.invoke(ProxyConnection.java:117)
                     at
    org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
                     at
    org.apache.tomcat.jdbc.pool.interceptor.AbstractCreateStatementInterceptor.invoke(AbstractCreateStatementInterceptor.java:79)
                     at
    org.apache.tomcat.jdbc.pool.JdbcInterceptor.invoke(JdbcInterceptor.java:108)
                     at
    org.apache.tomcat.jdbc.pool.DisposableConnectionFacade.invoke(DisposableConnectionFacade.java:81)
                     at com.sun.proxy.$Proxy4.setAutoCommit(Unknown Source)
                     at
    org.jooq.impl.DefaultConnectionProvider.setAutoCommit(DefaultConnectionProvider.java:219)
                     ... 36 common frames omitted
    Caused by: org.postgresql.util.PSQLException: An I/O error occurred
    while sending to the backend.
             at
    org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:350)
             at
    org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:481)
             at
    org.postgresql.jdbc.PgStatement.execute(PgStatement.java:401)
             at
    org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:164)
             at
    org.postgresql.jdbc.PgPreparedStatement.execute(PgPreparedStatement.java:153)
             at
    jdk.internal.reflect.GeneratedMethodAccessor25.invoke(Unknown Source)
             at
    java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
             at java.base/java.lang.reflect.Method.invoke(Method.java:564)
             at
    org.apache.tomcat.jdbc.pool.StatementFacade$StatementProxy.invoke(StatementFacade.java:114)
             at com.sun.proxy.$Proxy14.execute(Unknown Source)
             at
    org.jooq.tools.jdbc.DefaultPreparedStatement.execute(DefaultPreparedStatement.java:214)
             at org.jooq.impl.AbstractQuery.execute(AbstractQuery.java:458)
             at org.jooq.impl.AbstractQuery.execute(AbstractQuery.java:375)
             ... 50 common frames omitted
    Caused by: javax.net.ssl.SSLException: Socket closed
             at
    java.base/sun.security.ssl.Alert.createSSLException(Alert.java:127)
             at
    java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:369)
             at
    java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:312)
             at
    java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:307)
             at
    java.base/sun.security.ssl.SSLSocketImpl.handleException(SSLSocketImpl.java:1680)
             at
    java.base/sun.security.ssl.SSLSocketImpl$AppInputStream.read(SSLSocketImpl.java:1054)
             at
    org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:161)
             at
    org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:128)