Re: Phoenix JDBC Connection Warmup
As James suggested if you set the UPDATE_CACHE_FREQUENCY table property, the server will not be pinged for the latest metadata until the update frequency. Check out the altering section (https://phoenix.apache.org/) On Sun, Feb 3, 2019 at 5:57 PM William Shen wrote: > Thanks for the suggestions! > > Jaanai - do you mean to enable trace logging on the client side or on the > server side? > > James - no I have not tried setting it. I have not heard about the > configuration. Do you have a ball park suggestion on how to approach > setting this value? > On Sat, Feb 2, 2019 at 8:53 AM James Taylor > wrote: > >> Have you tried setting UPDATE_CACHE_FREQUENCY on your tables? >> >> On Fri, Feb 1, 2019 at 6:28 PM Jaanai Zhang >> wrote: >> >>> we experimented with issuing the same query repeatedly, and we observed a slow down not only on the first query >>> >>> I am not sure what the reasons are, perhaps you can enable TRACE log to >>> find what leads to slow, I guess that some meta information is reloaded >>> under highly write workload. >>> >>> >>>Jaanai Zhang >>>Best regards! >>> >>> >>> >>> William Shen 于2019年2月1日周五 上午2:09写道： >>> Thanks Jaanai. Do you know if that is expected only on the first query against a table? For us, we experimented with issuing the same query repeatedly, and we observed a slow down not only on the first query. Does it make sense to preemptively load table metadata on start up to warm up the system to reduce latency during the actual query time (if it is possible to do so)? On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang wrote: > It is expected when firstly query tables after establishing the > connection. Something likes loads some meta information into local cache > that need take some time, mainly including two aspects: 1. access > SYSTEM.CATALOG table to get schema information of the table 2. access the > meta table of HBase to get regions information of the table > > >Jaanai Zhang >Best regards! > > > > William Shen 于2019年1月31日周四 下午1:37写道： > >> Hi there, >> >> I have a component that makes Phoenix queries via the Phoenix JDBC >> Connection. I noticed that consistently, the Phoenix Client takes longer >> to >> execute a PreparedStatement and it takes longer to read through the >> ResultSet for a period of time (~15m) after a restart of the component. >> It >> seems like there is a warmup period for the JDBC connection. Is this to >> be >> expected? >> >> Thanks! >> >
Re: Phoenix JDBC Connection Warmup
Thanks for the suggestions! Jaanai - do you mean to enable trace logging on the client side or on the server side? James - no I have not tried setting it. I have not heard about the configuration. Do you have a ball park suggestion on how to approach setting this value? On Sat, Feb 2, 2019 at 8:53 AM James Taylor wrote: > Have you tried setting UPDATE_CACHE_FREQUENCY on your tables? > > On Fri, Feb 1, 2019 at 6:28 PM Jaanai Zhang > wrote: > >> we experimented with issuing the same query repeatedly, and we observed >>> a slow down not only on the first query >> >> I am not sure what the reasons are, perhaps you can enable TRACE log to >> find what leads to slow, I guess that some meta information is reloaded >> under highly write workload. >> >> >>Jaanai Zhang >>Best regards! >> >> >> >> William Shen 于2019年2月1日周五 上午2:09写道： >> >>> Thanks Jaanai. Do you know if that is expected only on the first query >>> against a table? For us, we experimented with issuing the same query >>> repeatedly, and we observed a slow down not only on the first query. Does >>> it make sense to preemptively load table metadata on start up to warm up >>> the system to reduce latency during the actual query time (if it is >>> possible to do so)? >>> >>> On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang >>> wrote: >>> It is expected when firstly query tables after establishing the connection. Something likes loads some meta information into local cache that need take some time, mainly including two aspects: 1. access SYSTEM.CATALOG table to get schema information of the table 2. access the meta table of HBase to get regions information of the table Jaanai Zhang Best regards! William Shen 于2019年1月31日周四 下午1:37写道： > Hi there, > > I have a component that makes Phoenix queries via the Phoenix JDBC > Connection. I noticed that consistently, the Phoenix Client takes longer > to > execute a PreparedStatement and it takes longer to read through the > ResultSet for a period of time (~15m) after a restart of the component. It > seems like there is a warmup period for the JDBC connection. Is this to be > expected? > > Thanks! >
Re: Phoenix JDBC Connection Warmup
Have you tried setting UPDATE_CACHE_FREQUENCY on your tables? On Fri, Feb 1, 2019 at 6:28 PM Jaanai Zhang wrote: > we experimented with issuing the same query repeatedly, and we observed a >> slow down not only on the first query > > I am not sure what the reasons are, perhaps you can enable TRACE log to > find what leads to slow, I guess that some meta information is reloaded > under highly write workload. > > >Jaanai Zhang >Best regards! > > > > William Shen 于2019年2月1日周五 上午2:09写道： > >> Thanks Jaanai. Do you know if that is expected only on the first query >> against a table? For us, we experimented with issuing the same query >> repeatedly, and we observed a slow down not only on the first query. Does >> it make sense to preemptively load table metadata on start up to warm up >> the system to reduce latency during the actual query time (if it is >> possible to do so)? >> >> On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang >> wrote: >> >>> It is expected when firstly query tables after establishing the >>> connection. Something likes loads some meta information into local cache >>> that need take some time, mainly including two aspects: 1. access >>> SYSTEM.CATALOG table to get schema information of the table 2. access the >>> meta table of HBase to get regions information of the table >>> >>> >>>Jaanai Zhang >>>Best regards! >>> >>> >>> >>> William Shen 于2019年1月31日周四 下午1:37写道： >>> Hi there, I have a component that makes Phoenix queries via the Phoenix JDBC Connection. I noticed that consistently, the Phoenix Client takes longer to execute a PreparedStatement and it takes longer to read through the ResultSet for a period of time (~15m) after a restart of the component. It seems like there is a warmup period for the JDBC connection. Is this to be expected? Thanks! >>>
Re: Phoenix JDBC Connection Warmup
> > we experimented with issuing the same query repeatedly, and we observed a > slow down not only on the first query I am not sure what the reasons are, perhaps you can enable TRACE log to find what leads to slow, I guess that some meta information is reloaded under highly write workload. Jaanai Zhang Best regards! William Shen 于2019年2月1日周五 上午2:09写道： > Thanks Jaanai. Do you know if that is expected only on the first query > against a table? For us, we experimented with issuing the same query > repeatedly, and we observed a slow down not only on the first query. Does > it make sense to preemptively load table metadata on start up to warm up > the system to reduce latency during the actual query time (if it is > possible to do so)? > > On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang > wrote: > >> It is expected when firstly query tables after establishing the >> connection. Something likes loads some meta information into local cache >> that need take some time, mainly including two aspects: 1. access >> SYSTEM.CATALOG table to get schema information of the table 2. access the >> meta table of HBase to get regions information of the table >> >> >>Jaanai Zhang >>Best regards! >> >> >> >> William Shen 于2019年1月31日周四 下午1:37写道： >> >>> Hi there, >>> >>> I have a component that makes Phoenix queries via the Phoenix JDBC >>> Connection. I noticed that consistently, the Phoenix Client takes longer to >>> execute a PreparedStatement and it takes longer to read through the >>> ResultSet for a period of time (~15m) after a restart of the component. It >>> seems like there is a warmup period for the JDBC connection. Is this to be >>> expected? >>> >>> Thanks! >>> >>
Re: Phoenix JDBC Connection Warmup
Thanks Jaanai. Do you know if that is expected only on the first query against a table? For us, we experimented with issuing the same query repeatedly, and we observed a slow down not only on the first query. Does it make sense to preemptively load table metadata on start up to warm up the system to reduce latency during the actual query time (if it is possible to do so)? On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang wrote: > It is expected when firstly query tables after establishing the > connection. Something likes loads some meta information into local cache > that need take some time, mainly including two aspects: 1. access > SYSTEM.CATALOG table to get schema information of the table 2. access the > meta table of HBase to get regions information of the table > > >Jaanai Zhang >Best regards! > > > > William Shen 于2019年1月31日周四 下午1:37写道： > >> Hi there, >> >> I have a component that makes Phoenix queries via the Phoenix JDBC >> Connection. I noticed that consistently, the Phoenix Client takes longer to >> execute a PreparedStatement and it takes longer to read through the >> ResultSet for a period of time (~15m) after a restart of the component. It >> seems like there is a warmup period for the JDBC connection. Is this to be >> expected? >> >> Thanks! >> >
Re: Phoenix JDBC Connection Warmup
It is expected when firstly query tables after establishing the connection. Something likes loads some meta information into local cache that need take some time, mainly including two aspects: 1. access SYSTEM.CATALOG table to get schema information of the table 2. access the meta table of HBase to get regions information of the table Jaanai Zhang Best regards! William Shen 于2019年1月31日周四 下午1:37写道： > Hi there, > > I have a component that makes Phoenix queries via the Phoenix JDBC > Connection. I noticed that consistently, the Phoenix Client takes longer to > execute a PreparedStatement and it takes longer to read through the > ResultSet for a period of time (~15m) after a restart of the component. It > seems like there is a warmup period for the JDBC connection. Is this to be > expected? > > Thanks! >
Phoenix JDBC Connection Warmup
Hi there, I have a component that makes Phoenix queries via the Phoenix JDBC Connection. I noticed that consistently, the Phoenix Client takes longer to execute a PreparedStatement and it takes longer to read through the ResultSet for a period of time (~15m) after a restart of the component. It seems like there is a warmup period for the JDBC connection. Is this to be expected? Thanks!
